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Terminal Posterior Tilted Implants Planned as a Sinus Graft Alternative for Fixed Full-Arch Implant-Supported Maxillary Restoration: A Case Series with 10- to 19-Year Results on 44 Consecutive Patients Presenting for Routine Maintenance
Abstract
Purpose
Posterior maxillary tilted implants are gaining prevalence as an alternative to sinus grafts supporting fixed maxillary restorations. This paper reports long-term results after loading using this technique.
Materials and Methods
Consecutive patients presenting for either routine hygiene maintenance or unplanned emergency care who had received tilted implants as a sinus graft alternative to support fixed fully implant-supported restoration of an edentulous maxilla and were followed for a minimum of 10 years from initial implant placement were included in this evaluation.
Results
Forty-four patients were identified: 40 with bilateral tilted implants and 4 with one tilted and one axial posterior implant. Eight patients received one-piece fixed porcelain-to-gold screw-retained restorations, and thirty-six patients received a fully implant-supported patient-removable Marius Bridge. Seventy-nine out of 84 originally loaded posterior tilted implants survived a minimum of 10 years loading; one tilted implant was lost at 10 years. Eight additional posterior implants were placed for either these lost tilted posterior implants or as proactive supplemental support; one of these replacement tilted implants survived for at least 10 years and is included in the data. All patients have maintained continuous fixed function throughout the follow-up period. Forty-one out of 44 patients continue with the original restoration, 33 without modification or removal of the fixed restoration or implant-connecting bar. One porcelain-to-gold and seven Marius Bridges had framework modifications to accommodate additional implants; 3 Marius Bridge restorations were replaced with a newer generation.
Conclusion
Within the limits of this retrospective study, the results show that continuous fixed function of fully implant-supported maxillary restorations using posterior tilted implants in terminal positions of support as a sinus graft alternative combined with axial anterior implants is possible over a prolonged period. Loss of a posterior tilted implant after loading is treatable with another tilted, zygomatic or axial implant, typically requiring only modification of the fixed restoration.
Randomized Clinical Trial of Maxillary Sinus Grafting using Deproteinized Porcine and Bovine Bone Mineral
Τρίτη, 21 Ιουνίου 2016, 10:22:30 πμ | Jung-Seok Lee, Hyun-Ki Shin, Jeong-Ho Yun, Kyoo-Sung Cho
Abstract
Background
Demineralized porcine bone mineral (DPBM) was recently developed and commercially available in maxillary sinus grafting, in which demineralized bovine bone mineral (DBBM) was widely used.
Objectives
The present randomized controlled clinical trial aimed to compare histological bone quality and radiographic volume stability in maxillary sinuses grafted with DPBM and DBBM.
Materials and Methods
Twenty sinuses in 16 participants were enrolled and randomly allocated to control and test groups using sequentially numbered, sealed envelopes; laterally approached sinus grafting with DBBM and DPBM, respectively. All participants were blinded to the group assignment during the entire experiment. After standardized osteotomy at the lateral wall of the maxillary sinus, the sinus membrane was elevated, and the control or test biomaterial was grafted. Computed tomography (CT) images were taken immediately after surgery, and another CT and trephine biopsy was taken for radiographic and histological analyses after 6 months. The histological bone quality was measured as a primary outcome, and changes in the height and volume of the graft were evaluated in the reconstructed CT images as secondary outcomes.
Results
Fifteen sites (7 and 8 sites for control and test group) in 11 participants were finally included in the per protocol (PP) analysis, and 16 sites (7 and 9 sites, respectively) in 12 participants were included in the intention-to-treat (ITT) analysis; there were four drop-outs and one minor protocol violation. In both statistical analyses, the test groups showed comparable new bone formation and residual biomaterials in histology, and both groups exhibited minimal volume/height changes in radiographies. However, smaller sizes of residual biomaterials were observed in the histological samples from the test compared to control sites, despite the use of the same sizes of both biomaterials.
Conclusions
The results suggested that DPBM might produce comparable bone formation and volumetric stability with DBBM in maxillary sinus grafting, however, further clinical study with longer-term periods and larger sample sizes should be needed for confirming this suggestion.
Short Implants (5 to 8 mm) Versus Longer Implants (>8 mm) with Sinus Lifting in Atrophic Posterior Maxilla: A Meta-Analysis of RCTs
Τρίτη, 14 Ιουνίου 2016, 2:05:29 πμ | Tengfei Fan, Yicun Li, Wei-Wei Deng, Tianfu Wu, Wenfeng Zhang
ABSTRACT
Objective
The specific purposes of this study were (1) to undertake a thorough systematic review and meta-analysis based only on randomized clinical trials (RCTs) to compare the rates of survival and complications of short implants to those of long implants; (2) to compare the surgical time and cost of short implants to those of long implants.
Methods
RCTs were identified from the major electronic databases (MEDLINE, Embase and Cochrane Library) using the keywords "dental implant," "short implant" and "atrophic maxilla," and a quantitative meta-analysis was conducted. The survival rate of implants and complications were the primary outcome measures, and other parameters assessed included costs and surgical time.
Results
Seven RCTs that met the inclusion criteria included 554 implants (265 implants in the short implant group). There was no significant difference in survival rate between two groups (RR: 1.00; 95% CI: [0.97, 1.03]; p = .96; seven trials, 554 participants). Compared with long implant group, the short implant group had a lower complications and the effect measure was significant (RR: 0.58; 95% CI: [0.37, 0.90]; p = .02; seven trials, 554 participants).
Conclusion
This systematic review showed that no difference between the survival rates of short implants (5–8 mm) and long implants (>8 mm); complications in short implants are lower than that in long implants. However, further studies are required to substantiate our findings.
Horizontal Ridge Augmentation using GBR with a Native Collagen Membrane and 1:1 Ratio of Particulated Xenograft and Autologous Bone: A 1-Year Prospective Clinical Study
Παρασκευή, 10 Ιουνίου 2016, 3:01:26 πμ | Meloni Silvio Mario, Jovanovic Sascha A, Urban Istvan, Canullo Luigi, Pisano Milena, Tallarico Marco
Abstract
Aim
To clinically and radiographically evaluate bone regeneration of severe horizontal bone defects.
Materials and Methods
This study was designed as a single cohort, prospective clinical trial. Partially or fully edentulous patients, having less then 4 mm of residual horizontal bone width were selected and consecutively treated with resorbable collagen membranes and a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, 7 months before implant placement. Tapered body implants were inserted and loaded 3 to 6 months later with a screw retained crown or bridge. Outcomes were: implant survival rate, any biological and prosthetic complications, horizontal alveolar bone dimensional changes measured on cone beam computed tomography (CBCT) taken at baseline and at implant insertion, peri-implant marginal bone level changes measured on periapical radiographs, plaque index (PI), and bleeding on probing index (BoP).
Results
Eighteen consecutive patients (11 females, 7 males) with a mean age of 56.8 years (range 24–78) and 22 treated sites received 55 regular platform implants. No patient dropped-out and no implants failed during the entire follow-up, resulting in a cumulative implant survival rate of 100%. No prosthetic or biological complications were recorded. Supraimposition of pre- and 7-month post-operative CBCT scans revealed an average horizontal bone gain of 5.03 ± 2.15 mm (95% CI: 4.13–5.92 mm). One year after final prosthesis delivery, mean marginal bone loss was 1.03 ± 0.21 mm (95% CI 0.83–1.17 mm). PI was 11.1% and BoP was 5.6%.
Conclusion
Within the limitation of the present study, high implant survival rate and high average bone augmentation seem to validate the use of collagen resorbable membranes with a 1:1 mixture of particulated anorganic bovine bone and autogenous bone, for the reconstruction of severe horizontal ridge defects.
A Retrospective Analysis of the Effectiveness of the Longevity Protocol for Assessing the Risk of Implant Failure
Τετάρτη, 8 Ιουνίου 2016, 9:08:48 πμ | Tiziano Testori, Carlo Clauser, Matteo Deflorian, Matteo Capelli, Francesco Zuffetti, Massimo Del Fabbro
ABSTRACT
Background
A new, computerized diagnostic tool, called the Longevity Protocol, was recently developed to predict implant failure. The present retrospective analysis was undertaken to assess the prognostic validity of this protocol.
Materials and Methods
A selected group of patients who had been treated with implants over the past 10 years at six dental clinics and experienced implant failure were included in the analysis. Another group of patients with similar characteristics, not experiencing implant failure, was used as control. In April of 2015, data about each of the patients was entered into the Longevity Protocol database. For each patient, the risk assessment produced by the protocol was compared to whether the implants eventually failed. The implant failure predictions and actual implant failures were compared.
Results
The Longevity Protocol analyzed the possible failure of 595 implants placed in 221 patients (323 implants placed in 138 patients classified as low risk, 180 implants placed in 55 patients classified as moderate risk, and 92 implants placed in 28 patients classified as high risk). The actual percentage of implant failure in the three groups was 10%, 15%, and 22%, respectively. The differences between the groups were statistically significant.
The sensitivity and specificity of the Longevity Protocol was 84.9% and 11.90% in the high/moderate risk group and 47.17% and 32.74% in the low risk group, respectively.
Conclusions
Statistically significant results were obtained. The Longevity Protocol reliably identified patients who risked implant failure. The protocol appears to be an important tool for prognosis assessment.
Long-term Evaluation of Peri-implant Bone Level after Reconstruction of Severely Atrophic Edentulous Maxilla via Vertical and Horizontal Guided Bone Regeneration in Combination with Sinus Augmentation: A Case Series with 1 to 15 Years of Loading
Δευτέρα, 30 Μαΐου 2016, 9:45:30 πμ | Istvan A. Urban, Alberto Monje, Jaime L. Lozada, Hom-Lay Wang
Abstract
Background
To the best of the authors' knowledge, there is very limited clinical data on the outcomes of simultaneous guided bone regeneration (GBR) for horizontal and/or vertical bone gain for the reconstruction of severely atrophic edentulous maxilla. Therefore, the purpose of the clinical series presented herein was to clinically evaluate long-term horizontal and vertical bone gain, as well as implant survival rate after reconstruction of severely atrophic edentulous maxillary ridges.
Material and Methods
Sixteen patients (mean age: 64.6 ± 14.6 years of age) were consecutively treated for vertical and/or horizontal bone augmentation via GBR in combination with bilateral sinus augmentation utilizing a mixture of autologous and anorganic bovine bone. Implant survival, bone gain, intraoperative/postoperative complications and peri-implant bone loss were calculated up to the last follow-up exam.
Results
Overall, 122 dental implants were placed into augmented sites and have been followed from 12 to 180 months (mean: 76.5 months). Implant survival was 100% (satisfactory survival rate of 97.5%). Mean bone gain was 5.6 mm (max: 9 mm; min: 3 mm) While vertical bone gain was 5.1 ± 1.8 mm; horizontal bone gain was 7.0 ± 1.5 mm. No intraoperative/postoperative complications were noted. Mean peri-implant bone loss values were consistent within the standards for implant success (1.4 ± 1.0 mm). At patient-level, only one patient who had three implants presented with severe peri-implant bone loss.
Conclusion
Complete reconstruction of an atrophied maxilla can be successfully achieved by means of guided bone regeneration for horizontal and/or vertical bone gain including bilateral sinus augmentation using a mixture of anorganic bovine bone and autologous bone.
Radiographic Evaluation of Maxillary Sinus Lateral Wall and Posterior Superior Alveolar Artery Anatomy: A Cone-Beam Computed Tomographic Study
Δευτέρα, 30 Μαΐου 2016, 9:40:28 πμ | Seyed Amir Danesh-Sani, Ali Movahed, Edgard S. ElChaar, King Chong Chan, Niloufar Amintavakoli
Abstract
Objective
The purpose of the current study is to assess the thickness of the maxillary sinus lateral wall in dentate and edentulous patients using cone beam computed tomography (CBCT). This study also provides information about the diameter, prevalence, and course of the posterior superior alveolar artery (PSAA), and its relation to the maxillary sinus floor.
Materials and Methods
Four hundred and thirty CBCT scans of the maxillofacial complex (860 maxillary sinuses) were reviewed. Measurements of the lateral wall of the maxillary sinus and PSAA were performed on the CBCT images.
Results
Statistical analysis showed that dental status (edentulous, non-edentulous) of the patients had no significant effect on the lateral wall thickness. The mean thickness of the lateral wall of the maxillary sinus was 1.21 ± 1.07 mm at the second molar (M2), 1.98 ± 1.87 mm at the first molar (M1), 2.02 ± 1.53 mm at the second premolar (P2) and 2.16 ± 1.25 mm at the first premolar (P1). There was statistically significant difference between the left and right sides of the maxillary sinus only at P2 (p =.043). Detection rate of the PSAA on CBCT was reported as 60.58%. The mean diameter of the artery was 1.17 mm (range 0.4–2.8 mm). There was no significant correlation between age and the size of the PSAA. The most frequent path of the PSAA was intraosseous (69.6%), followed by intrasinusal (24.3%) and superficial (6.1%). The overall mean distance of the PSAA from the floor of the maxillary sinus is 8.16 mm.
Conclusions
The results from this study suggest that using CBCT prior to the surgery provides valuable diagnostic information. However, undetected intraosseous canal in CBCT does not exclude its existence. Alteration in the lateral window design and the use of piezoelectric instruments are recommended if intraoperative complications are expected.
"Peri-Implantitis": A Complication of a Foreign Body or a Man-Made "Disease". Facts and Fiction
Δευτέρα, 30 Μαΐου 2016, 9:20:50 πμ | Albrektsson Tomas, Canullo Luigi, Cochran David, De Bruyn Hugo
Abstract
Background
The discrepancy between some scientific views and the daily clinical experience with dental implants has made the topic of "periimplantitis" highly controversial, especially the discussion whether "periimplantitis" should even be considered a "disease" or whether marginal bone loss instead would represent a complication of having a foreign body placed in the oral cavity.
Purpose
The aim of the present paper was to present the outcomes from a consensus meeting on "peri-implantitis" in Rome, Italy (January 8–10, 2016).
Materials and Methods
Seventeen clinical scientists were invited to, based on prepared reviews of the literature, discuss topics related to "periimplantitis."
Results and conclusions
Oral implants may lose bone or even display clinical failure. However, progressive bone loss threatening implant survival is rare and limited to a percent or two of all implants followed up over 10 years or more, provided that controlled implant systems are being used by properly trained clinicians. There is very little evidence pointing to implants suffering from a defined disease entity entitled "peri-implantitis." Marginal bone loss around implants is in the great majority of cases associated with immune-osteolytic reactions. Complicating factors include patient genetic disorders, patient smoking, cement or impression material remnants in the peri-implant sulcus, bacterial contamination of the implant components and technical issues such as loose screws, mobile components or fractured materials. These reactions combine to result in cellular responses with the end result being a shift in the delicate balance between the osteoblast and the osteoclast resulting in bone resorption. However, the great majority of controlled implants display a foreign body equilibrium resulting in very high survival rates of the implants over long term of follow-up.
Stability and Crestal Bone Behavior Following Simultaneous Placement of Multiple Dental Implants (Two or More) with the Bone Splitting Technique: A Clinical and Radiographic Evaluation
Τετάρτη, 18 Μαΐου 2016, 1:01:23 μμ | Sergio Alexandre Gehrke, José Eduardo Maté Sánchez de Val, Maria Piedad Ramírez Fernández, Jamil Awad Shibli, Paulo Henrique Orlato Rossetti, José Luis Calvo Guirado
Abstract
Purpose
The present study aimed to measure the implant stability quotient (ISQ) values at three different time points after surgical procedures and crestal bone behavior in multiple implants (two or more) installed simultaneously with the bone splitting technique.
Materials and Methods
For this study, 45 patients with different edentulous areas in the maxilla were selected, and a total of 114 dental implants were installed. Implant stability was measured by resonance frequency analysis immediately following implant placement to assess immediate stability (time 1) and stability at 90 days (time 2), and 150 days (time 3). Crestal bone height was measured in peri-apical radiographs at 90 and 150 days after implantation in relation to each implant shoulder, given that the implants were installed at the level of the crestal bone.
Results
Six implants were not osseointegrated. Overall, the means and standard deviations of the ISQ values were 60.3 ± 4.94 (95% confidence interval [CI], 44–69) at baseline, 66.6 ± 5.28 (95% CI, 49–75) at 90 days, and 72.1 ± 4.28 (95% CI, 59–79) at 150 days (p < 0.0001). The mean marginal bone loss of the implants was 1.11 ± 0.61 mm on the mesial side and 1.17 ± 0.61 mm on the distal side at time 2, and 1.73 ± 0.68 mm on the mesial side and 1.79 ± 0.70 mm on the distal side at time 3. A strong positive correlation between implant stability and bone loss was detected (p < 0.0001).
Conclusions
Within the limits of this study, the bone splitting technique with simultaneous implant installation exhibited a good success rate with respect to the osseointegration index but requires attention with respect to crestal bone behavior.
Dental Implants Placed in Periodontally Infected Sites in Humans
Δευτέρα, 16 Μαΐου 2016, 8:10:34 πμ | Roberto Crespi, Paolo Capparé, Giovanni Crespi, Giuseppe Lo Giudice, Giorgio Gastaldi, Enrico Gherlone
Abstract
Background
The purpose of the present study was to evaluate fresh socket implant outcome leaving granulomatous tissue into the bone defects.
Materials and Methods
Subjects requiring tooth extractions in periodontal infected sites were selected for this prospective study. Only patients with 4-wall defects and asymptomatic ones were included. The fresh sockets were randomly scheduled into two groups: In one group (Removal Group, RG) granulomatous tissue was removed and, in the other group (Left Group, LG) granulomatous tissue was left. Implants were positioned immediately after tooth extraction, and were loaded after 3 months in both groups. Intraoral digital radiographs were performed at temporary prosthesis placement; at 12, 24 and 36 months to evaluate marginal bone levels changes. Moreover, clinical parameters were acquired at the same time points.
Results
Sixty patients were included in this study. Three-hundred seventy-two implants were placed immediately after tooth extraction and, at 3-year follow-up, a survival rate of 98.66% was reported, 2 implants were lost in RG and 3 implants in LG. At 36-month follow-up, not statistically significant differences were found between RG and LG in marginal bone level changes and clinical parameters (p > 005). Moreover, not statistically significant differences were found in intragroup comparisons over time (p > 0.05).
Conclusions
With the limits of this study it was concluded that granulomatous tissue left in infected fresh sockets doesn't injury dental implant outcome.
Implant-Supported Immediately Loaded Fixed Full-Arch Dentures: Evaluation of Implant Survival Rates in a Case Cohort of up to 7 Years
Δευτέρα, 16 Μαΐου 2016, 6:55:27 πμ | Robert Niedermaier, Florian Stelzle, Max Riemann, Wolfgang Bolz, Paul Schuh, Hannes Wachtel
ABSTRACT
Background
The treatment of severely atrophied and edentulous jaws by means of fixed implant supported solutions is a challenging procedure.
Purpose
The immediate loading of four to six axial and tilted implants offers the possibility to overcome elaborate hard tissue augmentation procedures but lacks implant and patient related data on implant survival rates.
Materials and Methods
This retrospective 7-years clinical trial investigated the implant survival rates of 2,081 implants (380 patients, 482 jaws) using an immediate loading protocol with either 4, 5, or 6 implants per restoration. Survival rates were calculated concerning implantation related factors (jaws/number of supporting implants/angulations/diameters/lengths) and patient related factors (medical status/smoking).
Results
Overall survival of 2,081 implants was 97.0% on implant level. Survival rates of implantation related factors did not yield significant differences. Significant differences were yield between healthy patients and patients with osteoporosis (p = .002) and the medical status group "other" (p = .032), respectively. Smokers yielded a significantly higher survival than nonsmokers (p = .002).
Conclusions
It is assumed that four implants per jaw serve as a sufficient implant number for full arch restorations in both, the mandible and the maxilla. Osteoporosis under the medication with bisphosphonates seems to be a risk factor for implant survival. The authors suggest that the effect of smoking on ISRs remains controversial within this treatment concept.
Immediate Restoration of Immediate Implants in the Esthetic Zone of the Maxilla Via the Copy-Abutment Technique: 5-Year Follow-Up of Pink Esthetic Scores
Παρασκευή, 6 Μαΐου 2016, 6:40:28 πμ | Rudolf Fürhauser, Georg Mailath-Pokorny, Robert Haas, Dieter Busenlechner, Georg Watzek, Bernhard Pommer
Abstract
Background
Implant esthetics may benefit from individualized zirconia abutments copying the emergence profile of the natural tooth and delivered within days after immediate implant insertion.
Purpose
To investigate the esthetic outcome of the Copy-Abutment technique using the Pink Esthetic Score (PES).
Materials and Methods
A total of 77 patients with single-tooth implants in the anterior maxilla restored at the day of immediate implant placement using Copy-Abutments and provisional crowns were followed-up after 1 week, 1 month, 4 months, 6 months, 1, 2, 3, 4, and 5 years to assess implant esthetics.
Results
PES ranged between 7 and 14 (median: 13) and improved significantly between the 6 month and 1 year follow-up (p < .001), then remained stable up to the fifth year. Significant improvement was seen for the variables PES-6 soft tissue color (p = .002) and PES-7 soft tissue texture (p < .001) up to the 1 year follow-up, while PES-5 alveolar process deficiency deteriorated (p = .016). Mean mucosal recession was 0.26 ± 0.86 mm (range: 0–1.6) after 5 years and not related to gingival biotype.
Conclusion
Copy-Abutments for immediate restoration of implants in the esthetic zone show satisfactory long-term esthetic outcomes.
Immediate Implant Placement in Sockets with Asymptomatic Apical Periodontitis
Παρασκευή, 29 Απριλίου 2016, 3:51:47 πμ | Roberto Crespi, Paolo Capparé, Giovanni Crespi, Giuseppe Lo Giudice, Giorgio Gastaldi, Enrico Gherlone
Abstract
Background
The purpose of the present study was to evaluate if the presence of granulation tissue in asymptomatic apical periodontitis compromised immediate implant placement.
Methods
Patients requiring extraction of one tooth (maxillary and mandibular incisive, canine or premolar) with asymptomatic apical periodontitis, were recruited for this prospective study. They were randomly scheduled into two groups: in first group (A) including 30 teeth, reactive soft tissue was debrided before implant placement, and in second group (B) including 30 teeth, reactive soft tissue was left in the apical lesion. Implants were positioned immediately after tooth extraction, and were loaded after 3 months in both groups. Cone beam computed tomography was performed before tooth extraction and at 1-year follow-up to evaluate the radiolucency around the root apex and the implant, bucco-lingual bone levels were also checked.
Results
Sixty patients were included in this study. Sixty implants were placed immediately after tooth extraction and, at 1-year follow-up, a survival rate of 100% was reported. After one year both groups showed absence of radiolucent zone at the apical region of implants. All fresh sockets presented a buccal-palatal bone reduction in both groups after one year, even if not statistically significant differences were found between baseline bone levels and within groups.
Conclusions
Within the limitations of the present study, the immediate placement of implants into the extraction sockets with asymptomatic apical periodontitis, in presence of primary stability, did not lead to an increased rate of complications and rendered an equally favorable type of tissue integration.
Mandibular Full-Arch Fixed Prostheses Supported on 4 Implants with Either Axial Or Tilted Distal Implants: A 3-Year Prospective Study
Παρασκευή, 29 Απριλίου 2016, 3:33:31 πμ | Stefan Krennmair, Michael Weinländer, Michael Malek, Thomas Forstner, Gerald Krennmair, Michael Stimmelmayr
Abstract
Purpose
This prospective study evaluated the clinical and radiographic outcome of distally cantilevered 4-implant-supported fixed mandibular prostheses (4-ISFMP) with distal implants either in axial or distally tilted direction.
Material and Methods
Forty-one mandibulary edentulous patients received acrylic veneered 4-ISFMP with casted framework. Based on distal implant placement direction patients were assigned to 2 groups: 21 patients with four (2 anterior/2 posterior) axial implants (axial-group I) and 20 patients with 2 anterior axial/2 distal tilted implants (tilted-group II). Patients were prospectively followed for 3 years by annual examinations of implants and prosthetic survival rates including assessment for biological and mechanical complications. Additionally, peri-implant marginal bone resorption [MBR], pocket depth [PD], plaque index [PI], bleeding index [BI] and gingival index [GI], and calculus index [CI] were evaluated at each annual follow-up.
Results
37/41 patients (19 axial-group I, 18 tilted-group II) and 148/164 implants were followed at the 1-, 2-, and 3-year evaluation (dropout rate: 11.8%) presenting no implant and denture loss (100% survival). The overall, MBR at year 1, 2, and 3 was 1.11 ± 0.4 mm, 1.26 ± 0.42 mm, and 1.40 ± 0.41 mm, respectively, representing a significant (p < .001) continuing time depending annual reduction. MBR and PD did not differ between anterior and posterior regions in both groups or for anterior and posterior regions between the groups. PI and CI were significantly (p < .001) higher for implants in anterior regions than for posterior regions in both groups. Moreover, posterior implant regions showed significantly (p < .001) higher PI and CI for axial-group I than for tilted-group II over time. Biological and mechanical complications as well as GI and BI did not differ between the groups over a 3-year follow-up period.
Conclusion
For clinical implant and prosthesis outcome no statistical significant mean differences were noted for distally cantilevered 4-ISFMP supported by distal implants placed in tilted or axial direction.
Long-Term Outcomes of Early Loading of Straumann Implant-Supported Fixed Segmented Bridgeworks in Edentulous Maxillae: A 10-Year Prospective Study
Παρασκευή, 8 Απριλίου 2016, 12:16:25 μμ | Xiao-Xiao Zhang, Jun-Yu Shi, Ying-Xin Gu, Hong-Chang Lai
Abstract
Background
There have been few studies investigating the long-term outcome of early-loaded implants with segmented bridgeworks on fully edentulous maxillae.
Purpose
To evaluate the long-term predictability of early-loaded Straumann implant-supported fixed segmented bridgeworks in edentulous maxillae.
Material and Methods
Ninety-one implants were placed in 12 patients with edentulous maxillae. After a healing period of 6 weeks, the abutments were tightened followed by cementing of fixed full-arch prostheses. The patients were recalled after 1, 3, 5, and 10 years of loading for clinical evaluation. Implant success rate, peri-implant soft tissue condition, technical complications, marginal bone loss and patients' satisfaction was assessed.
Results
Eleven of the 12 patients attended the 10-year follow-up. Two implants were lost. The implant success rate was 97.6% at implant level and 81.8% at patient level. The mean marginal bone loss was found to be 0.41 ± 0.55mm, 0.53 ± 0.43mm, 0.68 ± 0.76 mm and 1.01 ± 0.85 mm at the 1, 3, 5, and 10-year follow-up respectively. None of the 11 patients showed a modified plaque index (mPLI) or modified bleeding index (mBI) of 3. Only one patient was found to have pocket probing depth (PPD) exceeding 3 mm. Peri-implantitis was found around one of the implants in a patient after 4 years of loading. The success rate of prostheses was 55.3% at prosthesis level and 27.3% at patient level. The most common technical complication of the prostheses was chipping of the ceramic veneer. Damaged veneers were observed in five patients. Other complications were loss of retention and abutment loosening.
Conclusion
Early loading of Straumann SLA implants for support of full-arch segmented bridgeworks represents a viable therapy for the fully edentulous maxillae in the long term. High success rate of implants, acceptable peri-implant soft tissue condition and excellent patient satisfaction can be achieved, while technical complications of prostheses are common.
Radiological and Biological Assessment of Immediately Restored Anterior Maxillary Implants Combined with GBR and Free Connective Tissue Graft
Δευτέρα, 21 Μαρτίου 2016, 5:07:52 πμ | Roni Kolerman, Joseph Nissan, Arkadi Rahmanov, Eran Zenziper, Shimshon Slutzkey, Haim Tal
Abstract
Objectives
Radiologic and biologic assessment of immediately restored Implants combined with guided bone regeneration (GBR) and free connective tissue graft.
Methods
1–4 year retrospective study involving 34 patients treated with maxillary immediately restored anterior single-implants. Soft tissue dimensions, radiographic bone loss, and biological and prosthetic complications were assessed.
Results
During the mean follow up period of 29 months the study group presented a mean mesial bone loss of 1.10 ± 0.39 mm (range: 0.5–2.4 mm), and mean distal bone loss of 1.19 ± 0.41 mm (range: 0.4–2.1 mm). Mean periimplant probing depth of 3.49 mm (SD ± 1.06) and 2.35 (SD ± 0.52) for the contralateral tooth (highly significant p < 0.001). Bleeding on probing was present in 29.4% of the examined implant supported crown sites and 10.4% of the contralateral teeth (p < 0.001).
Conclusions
Anterior maxillary single-tooth replacement, using GBR and connective tissue graft according to the concept of immediate implant placement, and non-functional restoration is an accepted treatment modality achieving favorable peri-implant soft tissue condition.
Esthetic Outcome of Implant Supported Crowns With and Without Peri-Implant Conditioning Using Provisional Fixed Prosthesis: A Randomized Controlled Clinical Trial
Πέμπτη, 17 Μαρτίου 2016, 5:00:40 πμ | David Furze, Ashley Byrne, Sonia Alam, Julia-Gabriela Wittneben
Abstract
Background
Achieving an optimal esthetic result using dental implants is challenging. Fixed implant-supported provisional crowns are often used to customize the emergence profile and to individualize the surrounding peri-implant soft tissue.
Purpose
The objective of this study is to evaluate whether the use of a provisional implant-supported crown leads to an esthetic benefit on implants that are placed in the esthetic zone. The null hypothesis is that there is no-difference between the two study groups.
Material and methods
Twenty single implants (Bone Level, Straumann AG, Basel, Switzerland) were inserted in consecutive patients. After reopening, a randomization process assigned them to either cohort group 1: a provisional phase with soft tissue conditioning using the "dynamic compression technique" or cohort group 2: without a provisional. Implants were finally restored with an all-ceramic crown. Follow-up examinations were performed at 3 and 12 months including implant success and survival, clinical, and radiographic parameters.
Results
After 1 year all implants successfully integrated, mean values of combined modPES and WES were 16.7 for group 1 and 10.5 for Group 2. This was statistically significant. Mean bone loss after 1 year was −0.09 and −0.08 for groups 1 and 2, respectively, without being statistically significant.
Conclusion
A provisional phase with soft tissue conditioning does improve the final esthetic result.
3-Year Randomized Controlled Prospective Clinical Trial on Different CAD-CAM Implant Abutments
Δευτέρα, 14 Μαρτίου 2016, 2:39:54 μμ | Marco Ferrari, Maria Gabriella Tricarico, Maria Crysanti Cagidiaco, Alessandro Vichi, Enrico Felice Gherlone, Fernando Zarone, Roberto Sorrentino
Abstract
Background
Zirconia abutments were introduced to restore esthetic regions and showed sufficient stability to support implant restorations. Nonetheless, to date the observation periods are shorter than those of titanium abutments.
Purpose
To assess the survival of implant crowns supported by computer aided design-computer aided manufacturing (CAD-CAM) abutments after 3 years.
Materials and Methods
Fifty-six patients were selected for this prospective clinical study. Each patient received at least 1 titanium implant for a total of 89 fixtures. A two-stage surgical technique and no additional soft or hard tissue graft were used. The implants were randomly divided into 3 groups receiving different CAD-CAM abutments: titanium, titanium nitride, and zirconia. Zirconia or metal-ceramic crowns were used as final restorations. Cementation was the baseline and the restorations were checked after 6 months, 1, 2, and 3 years, assessing any mechanical complication. Statistical analyses were performed to evaluate the 3-year success rates.
Results
Five failures were reported in the zirconia group; all the failed restorations showed fractures of the abutment connection. Four failures occurred in posterior regions and one more occurred while screwing the abutment. Titanium and titanium nitride abutments had significantly higher 3-year success rates than zirconia abutments (p < .05).
Conclusions
Atlantis titanium and titanium nitride abutments showed optimal clinical performances after 3 years. Conversely, Atlantis zirconia abutments should be avoided to restore posterior regions.
Antihypertensive Medications and the Survival Rate of Osseointegrated Dental Implants: A Cohort Study
Πέμπτη, 3 Μαρτίου 2016, 10:18:08 πμ | Xixi Wu, Khadijeh Al-Abedalla, Hazem Eimar, Sreenath Arekunnath Madathil, Samer Abi-Nader, Nach G. Daniel, Belinda Nicolau, Faleh Tamimi
Abstract
Purpose
Antihypertensive drugs in general are beneficial for bone formation and remodeling, and are associated with lower risk of bone fractures. As osseointegration is influenced by bone metabolism, this study aimed to investigate the association between antihypertensive drugs and the survival rate of osseointegrated implants.
Materials and Methods
This retrospective cohort study included a total of 1,499 dental implants in 728 patients (327 implants in 142 antihypertensive-drugs-users and 1,172 in 586 nonusers). Multilevel mixed effects parametric survival analyses were used to test the association between antihypertensive drugs use and implant failure adjusting for potential confounders.
Results
Only 0.6% of the implants failed in patients using antihypertensive drugs while 4.1% failed in nonusers. A higher survival rate of dental implants was observed among users of antihypertensive drugs [HR (95% CI): 0.12 (0.03–0.49)] compared to nonusers.
Conclusions
Our findings suggest that treatment with antihypertensive drugs may be associated with an increased survival rate of osseointegrated implants. To our knowledge, this could be the first study showing that the systemic use of a medication could be associated with higher survival rate of dental implants.
Ridge Preservation Using Composite Alloplastic Materials: A Randomized Control Clinical and Histological Study in Humans
Abstract
Aim
To evaluate (clinically, histologically, and histo-morphometrically) the use of composite materials (Biphasic calcium sulphate [BCS] with β Tri-Calcium Phosphate (β-TCP) and Hydroxyapatite [HA]) in extraction socket sites and compare it to un-disturbed natural healing.
Material and Methods
Prospective clinical trial of 36 patients (40 extraction sockets) were randomly assigned to either test or control group. Alveolar ridge horizontal dimension was measured in the middle of the socket at crest and 3 and 6 mm subcrestally. Crestal vertical height was measured at baseline surgery and at 4 month re-entry, at which time bone core biopsies were harvested from the center of the edentulous ridge. Histo-morphometric evaluation of the samples was performed using hematoxylin & eosin stains and morphometric software.
Results
The change in horizontal ridge width was higher in the control compared to the experimental group: 2.28 ± 2.36 mm versus 0.03 ± 2.32 mm (p = .007) at −3 mm and 2.28 ± 2.43 versus 0.035 ± 3.05 (p = .02) at −6 mm, for the experimental and control sites, respectively. The vertical distance form bone crest to neighboring horizontal line interconnecting the neighboring teeth was minimal in both groups (0.307 ± 2.01 mm versus 0.14 ± 2.03 mm [p = 0.41]). Residual scaffolds occupied 15.99 ± 11.4% of the volume in the grafted (test) sites while bone area fraction was not statistically different among the groups (47.7 ± 10.6% versus 52.6 ± 11.6%, test versus control, respectively p = .39). The percentage of connective tissue in the control group was significantly higher that test group (36.3 ± 19.4% versus 46.7 ± 10.6% test versus control, respectively, p = .013).
Conclusion
Ridge preservation technique using a combination of two synthetic bone grafts β-TCP and HA with BCS resulted in greater stability in the horizontal dimension after 4 months.
Large Bone Vertical Augmentation Using a Three-Dimensional Printed TCP/HA Bone Graft: A Pilot Study in Dog Mandible
Δευτέρα, 22 Φεβρουαρίου 2016, 5:46:06 πμ | Jean-Pierre Carrel, Anselm Wiskott, Susanne Scherrer, Stéphane Durual
Abstract
Background
Osteoflux is a three-dimensional printed calcium phosphate porous structure for oral bone augmentation. It is a mechanically stable scaffold with a well-defined interconnectivity and can be readily shaped to conform to the bone bed's morphology.
Purpose
An animal experiment is reported whose aim was to assess the performance and safety of the scaffold in promoting vertical growth of cortical bone in the mandible.
Materials and methods
Four three-dimensional blocks (10 mm length, 5 mm width, 5 mm height) were affixed to edentulous segments of the dog's mandible and covered by a collagen membrane. During bone bed preparation, particular attention was paid not to create defects 0.5 mm or more so that the real potential of the three-dimensional block in driving vertical bone growth can be assessed. Histomorphometric analyses were performed after 8 weeks.
Results
At 8 weeks, the three-dimensional blocks led to substantial vertical bone growth up to 4.5 mm from the bone bed. Between 0 and 1 mm in height, 44% of the surface was filled with new bone, at 1 to 3 mm it was 20% to 35%, 18% at 3 to 4, and ca. 6% beyond 4 mm. New bone was evenly distributed along in mesio-distal direction and formed a new crest contour in harmony with the natural mandibular shape.
Conclusions
After two months of healing, the three-dimensional printed blocks conducted new bone growth above its natural bed, up to 4.5 mm in a canine mandibular model. Furthermore, the new bone was evenly distributed in height and density along the block. These results are very promising and need to be further evaluated by a complete powerful study using the same model.
Clinical Outcomes of Implants Placed in Extraction Sockets and Immediately Restored: A 7-Year Single-Cohort Prospective Study
Τετάρτη, 17 Φεβρουαρίου 2016, 5:57:20 πμ | Antonio Barone, Simone Marconcini, Enrica Giammarinaro, Eitan Mijiritsky, Federico Gelpi, Ugo Covani
Abstract
Background
The placement of implants immediately after tooth extraction has proven to be a predictable treatment strategy with a very high success rate.
Purpose
The aim of the present 7-year prospective single cohort study was to evaluate the success rate, marginal bone level (MBL), soft tissue stability of implants placed in fresh extraction sockets and immediately restored.
Material and Methods
This prospective cohort study included 37 implants in 32 patients (19 females and 13 males) with an average age of 40.1 ± 13.3 (range: 21–63 years) who received immediate implants and immediate single unit restorations. Outcome evaluations were: implant failures, complications, MBL, width of keratinized gingiva, facial soft tissue (FST) levels, modified Plaque Index and modified Bleeding Index.
Results and Conclusions
The cumulative survival rate was of 94.6% at 7-year visit. The mean MBL was −0.6 ± 0.49 mm at baseline and 1 ± 0.2 mm after 7 years. The FST Level was 0.4 ± 0.69 mm at baseline and 0.02 ± 0.70 mm at the 7-year follow-up. The Width of Keratinazed Gingiva was 3.8 ± 0.47 mm at baseline and 3.1 ± 0.42 mm at 7-year follow-up. Implants placed immediately after tooth extraction and immediately restored showed predictable clinical outcomes in this prospective study.
Stability and Marginal Bone Level Changes of SLActive Titanium-Zirconium Implants Placed with Flapless Surgery: A Prospective Pilot Study
Δευτέρα, 15 Φεβρουαρίου 2016, 2:11:09 πμ | Pinar Altinci, Gulsen Can, Onur Gunes, Caner Ozturk, Hakan Eren
Abstract
Background
Immediately-loaded, narrow-diameter implants can be a less invasive alternative for the implant-supported fixed rehabilitation of narrow, posterior crests.
Purpose
To determine the stability and marginal bone level (MBL) changes of narrow-diameter, titanium-zirconium (TiZr) implants placed with flapless surgery and loaded immediately in the posterior region.
Materials and Methods
Thirty-eight TiZr implants (3.3 mm diameter, 10 mm length, Roxolid, Straumann AG) were placed in the posterior crests of 14 patients with computer-guided flapless surgery as a support of 3-unit posterior bridges. Eighteen implants were loaded immediately, and 20 implants were loaded conventionally. The implant stability quotients were determined at the 1, 2, 4, and 8. weeks of healing before conventional loading, and at the 3, 6, and 12. months after loading by resonance frequency analysis. The MBL changes were measured by digital radiography.
Results
The surgical protocols were accomplished without any biological complications. There was no significant difference in the stability changes of TiZr implants between the loading groups (p > .05). The MBL changes were −0.18 ± 0.27 mm and −0.24 ± 0.27 mm at the 12. month of immediate and conventional loading, respectively, which was not statistically significant (p > .05).
Conclusion
The stability and MBL changes of TiZr implants supporting posterior 3-unit bridges were clinically acceptable at the first year of loading.
The Risk of Prion Infection through Bovine Grafting Materials
Τρίτη, 9 Φεβρουαρίου 2016, 4:52:12 πμ | Yeoungsug Kim, Angel Emmanuel Rodriguez, Hessam Nowzari
Abstract
Background
Bovine-derived grafting materials are frequently used in a variety of bone augmentation techniques. The aim of this paper is to assess the unique safety issue of bovine-derived grafting materials that is rarely addressed in dental literature: risk of bovine spongiform encephalopathy (BSE).
Methods
The validity of the current BSE diagnostic methods, surveillance and epidemiological trends in affected countries, and BSE infectivity in bovine bone before and after manufacturing processing were reviewed and analyzed.
Results
Prion screening has significant limits. Humans are not safe from the infection of prion disease of other species. Prions can and do break the species barrier. There is evidence there may be tens of thousands of infectious carriers in the western countries alone. This raises concern about the potential for perpetuation of infection via medical procedures.
Conclusion
The limited ability to screen prions within the animal genome, along with a long latency period to manifestation of the disease (1 to over 50 years) in infected patients, provides a framework for discussing posible long-term risks of the xenografts that are used so extensively in dentistry. We suggest abolishing the use of bovine bone.
A Systematic Review of Outcomes Following Immediate Molar Implant Placement Based on Recently Published Studies
Abstract
Background
Immediate implant placement in molar extraction sites has become a treatment option for experienced clinicians.
Purpose
The aim of this study was to provide a systematic review and meta-analysis of outcomes from recent clinical studies with immediate molar implants.
Materials and Methods
A systematic review was undertaken of relevant literature published from November 2008 to May 2015. Data collected included implant survival rates after at least 1 year in function, cumulative crestal bone loss, and implant location (maxilla vs mandible) and diameter. Implant diameters were grouped as "wide" (4–6 mm) or "ultra-wide" (>6–9 mm). Survival and bone loss with 95% CIs were calculated using a random effects model. Meta-analysis techniques were used to compare survival rates and cumulative mean bone loss between immediate and delayed placement implants. Survival rates also were computed and compared between wide and ultra-wide implants using chi-square testing. The quality of each study was assessed using established criteria.
Results
The literature search provided 15 papers published between November 2008 and May 2015 that satisfied the inclusion criteria. Data on survival were found for a total of 768 immediate molar implants inserted in 757 patients. Meta-analysis of these data showed an implant survival rate of 98% with no difference between maxilla and mandible. Five studies included delayed molar implants as controls, and no significant differences were detected. A significant difference (p = .048) was found in relation to implant diameter with implant failures being higher (3.67 vs 1.45%) for ultra-wide (>6–9 mm) versus wide (4–6 mm) implants. The majority of the 15 studies were determined to be either "average" (prospective case series) or "fair" (retrospective) in quality.
Conclusion
While there are still no published reports from double-blind, randomized, controlled (best quality) clinical trials of immediate molar implant placement, high survival rates have been reported. The present data, however, suggests that there may be an optimal diameter for this implant application. Meta-analysis of the limited bone loss data reported estimated the overall mean cumulative bone loss after at least 1 year to be 0.57 mm.
The Performance of Titanium-Zirconium Implants in the Elderly: A Biomechanical Comparative Study in the Minipig
Abstract
Objectives
The aim of this study was to test the following hypothesis: (1) Aging would adversely affect bone integration of implants; (2) Titanium-zirconium-SLActive (TiZr-SLActive) implant might perform better in osseointegration than Ti-SLA implant in aged group.
Materials and Methods
Thirteen miniature pigs (six of them were young adult minipigs, with other seven being aged ones.) were enrolled in this study. The right mandibular premolars (P1, P2, P3) and the first molar (M1) were extracted in all animals. Three months later, one TiZr-SLActive and one Ti-SLA implants were inserted into the endentulous area in mandible of each animal. The animals were sacrificed 8 weeks after placement of implants. Implants in the mandibles were used for removal torque (RT) tests, while vertebra and femur being retrieved for bone mineral density (BMD) tests.
Results
Implant success rate in the young group was significantly higher than that in the aged group. Higher survival rate of implants was also observed in younger group than that in the aged group but without significant difference. Within the young group, mean value for peak RT of Ti-SLA implants was higher than that of TiZr-SLActive implants without significant difference. In the aged group, the TiZr-SLActive implants showed a higher mean value for peak RT than Ti-SLA implants. No significant difference was found in the mean BMD in both vertebra and femur between different age groups.
Conclusions
Within the limits of this study, aging could negatively affect osseointegration of dental implants. TiZr-SLActive implants might to some degree compensate for the compromise in osseointegration brought by aging.
A 15-Year Comparative Prospective Study of Surgical and Prosthetic Care and Aftercare of Overdenture Treatment in the Atrophied Mandible: Augmentation Versus Nonaugmentation
Πέμπτη, 17 Δεκεμβρίου 2015, 2:31:58 πμ | Anita Visser, Cornelis Stellingsma, Gerry M Raghoebar, Henny JA Meijer, Arjan Vissink
Abstract
Background
Different treatment strategies for the atrophied mandible are described in literature. The need for long term care and aftercare for these strategies is sparsely described, however.
Purpose
To prospectively assess the need for prosthetic and surgical care and aftercare of two implant treatment strategies for the atrophied mandible.
Materials and Methods
Forty edentulous elderly patients were randomly assigned according to a balanced allocation method to a treatment strategy: dental implants in combination with an augmentation procedure versus a nonaugmentation procedure. All surgical and prosthetic care and aftercare were scored from the first visit until 15 years after implant placement.
Results
Twenty elderly patients completed the 15-year follow-up. As expected, the augmentation group needed significantly more surgical time than the nonaugmentation group (338 vs 145 minutes), but the need for prosthetic care and surgical/prosthetic aftercare was comparable. Implant survival was lower in augmented mandibles (88.7% vs 98.7%, p < .05). Aftercare mainly consisted of routine inspections; the need for prosthetic adjustments was minor. Surgical aftercare was hardly needed.
Conclusion
The only difference in the need for surgical and prosthetic (after) care was the extra time needed for performing augmentation surgery and the higher risk on implant loss in augmented mandibles. Otherwise, the need for care and aftercare was of the same magnitude. Thus, when applicable, nonaugmentation surgery is preferred as no general anesthesia is needed and the morbidity is low.
Immediate Implants Placed in Fresh Sockets Associated with Periapical Pathology: A Split-Mouth Design and Survival Evaluation after 1-Year Follow-Up
Πέμπτη, 17 Δεκεμβρίου 2015, 2:28:42 πμ | Cristina Hita-Iglesias, Francisco J. Sánchez-Sánchez, Javier Montero, Pablo Galindo-Moreno, Francisco Mesa, Ildefonso Martínez-Lara, Elena Sánchez-Fernández
Abstract
Purpose
To compare the immediate implant success rates between sites with chronic apical lesions and healthy sites in the same patients 1 year postdelayed loading.
Materials and Methods
One hundred sixty-eight immediate implants were placed in sixty patients at upper incisor, canine, and premolar sites. A split-mouth design was used, placing a minimum of two implants, one in a fresh socket associated with chronic periapical disease, the average lesion size was larger than 4 mm and less than 8 mm (test group), and the other(s) in a healthy fresh socket (control group). Implant survival rate at 1 year postloading delayed was compared between the groups.
Results
The implant survival rate was 98.2% for the total sample (n = 168); out of the three implants lost, two were from the test group, and one was from the control group (in the same patient as one of the former). Among the surviving implants, five were also considered failures due to excessive bone loss (n = 3) and also because of the recurrence of the periapical lesions (n = 2). Survival rates were significantly lower in the test than control sites at 12 months postloading.
Conclusions
Implant survival rates were significantly lower after the immediate implantation in postextraction sockets associated with chronic periapical disease (90.8%) than in healthy postextraction sockets (98.1%).
The Esthetic Effect of Veneered Zirconia Abutments for Single-Tooth Implant Reconstructions: A Randomized Controlled Clinical Trial
Πέμπτη, 17 Δεκεμβρίου 2015, 2:27:30 πμ | Daniel S Thoma, Francine Brandenberg, Vincent Fehmer, Nathalie Knechtle, Christoph HF Hämmerle, Irena Sailer
Abstract
Purpose
The purposes of this study were to test whether or not veneering of the submucosal part of zirconia abutments can positively influence the esthetic outcome compared with nonveneered zirconia abutments; to evaluate the influence of the mucosal thickness on the esthetic outcomes of the veneered and nonveneered abutments; and to evaluate the thickness of the peri-implant mucosa compared with the thickness of the gingiva of contralateral tooth sites.
Materials and Methods
Forty-four single-tooth implants in 44 patients were randomly restored with either cemented (CR) or screw-retained (SR) reconstructions based on white zirconia abutments (CR-W, SR-W) or pink-veneered zirconia abutments (CR-P, SR-P). Esthetic outcome measurements were performed based on a spectrophotometric evaluation of the peri-implant mucosal color. In addition, the thickness of the mucosa was measured. A two-way analysis of variance was conducted to test the effect of veneering (pink vs white) and mucosa thickness (<2 mm vs ≥2 mm) on the calculated color difference ΔE for pooled data of CR and SR reconstructions (p < .05).
Results
Analyses grouping the sites according to veneering of the abutments and mucosal thickness demonstrated less discoloration for sites with a veneered abutment irrespective of the mucosal thickness: ΔE 4.50 ± 1.93 (<2 mm) and ΔE 6.88 ± 2.45 (≥2 mm); CR-P, SR-P) compared with sites without veneering ΔE 9.72 ± 3.82 (<2 mm; CR-W, SR-W) and ΔE 8.31 ± 2.98 (≥2 mm). The differences between veneered and nonveneered abutments were significant (p = .032).
Conclusions
Veneering of zirconia abutments with pink veneering ceramic positively influenced the peri-implant mucosal color.
In-Vitro Study of the Contamination Remaining on Used Healing Abutments after Cleaning and Sterilizing in Dental Practice
Δευτέρα, 7 Δεκεμβρίου 2015, 10:56:51 πμ | Chandur Wadhwani, Todd R. Schonnenbaum, Franco Audia, Kwok-Hung Chung
Abstract
Background
Reuse or "recycle" of dental implant healing abutments in clinical practice is common, primarily for economic rational.
Purpose
To determine of this practice results in reuse of components that carry with them some degree of contamination between patients, even following thorough cleaning and sterilization.
Materials and Methods
One hundred healing abutments were collected from eight clinicians following patient use. The abutments were cleaned, sterilized, and then collected. The samples were treated with a protein specific stain (Phloxine B), and photographed.
Results
Ninety-nine percent of the abutments showed protein contamination at one or more sites following cleaning and sterilization.
Conclusion
Reuse of healing abutments between patients should be reevaluated in light of this data.
Addition of a Synthetically Fabricated Osteoinductive Biphasic Calcium Phosphate Bone Graft to BMP2 Improves New Bone Formation
Πέμπτη, 29 Οκτωβρίου 2015, 12:49:12 πμ | Yufeng Zhang, Shuang Yang, Wei Zhou, Hang Fu, Li Qian, Richard J. Miron
Abstract
Background
Bone morphogenetic protein-2 (BMP2) has been successfully utilized in dentistry to promote new bone formation because of its osteoinductive ability to recruit mesenchymal progenitor cells and induce their differentiation to bone-forming osteoblasts. Recently, novel biphasic calcium phosphate scaffolds have been developed with similar osteoinductive properties capable of forming ectopic bone formation.
Purpose
The aim of the present study was to assess whether the combination of BMP2 with this novel Biphasic Calcium Phosphate (BCP) scaffold may additionally promote new bone regeneration.
Materials and Methods
Cylindrical bone defects measuring 2.5 mm were created bilaterally in the femurs of 18 Wistar rats. After 4 weeks, the following six groups were assessed for new bone formation by micro-computed tomography (CT) as well as histological assessment: 1) collagen scaffolds + 20 μg of BMP2; 2) collagen scaffolds + 50 μg of BMP2; 3) collagen scaffolds + 100 μg of BMP2; 4) BCP scaffolds + 20 μg of BMP2; 5) BCP scaffolds + 50 μg of BMP2; and 6) BCP scaffolds + 100 μg of BMP2. Furthermore, tartrate-resistant acid phosphatase (TRAP) staining was utilized to assess osteoclast activity and osteoclast number. The release kinetics of BMP2 from both BCP and collagen scaffolds was investigated over a 14-day period.
Results
The results from present study demonstrate that BMP2 is able to promote new bone formation in a concentration dependant manner when loaded with either a collagen scaffolds or BCP scaffolds. Micro-CT analysis demonstrated significantly higher levels of new bone formation in groups containing BCP + BMP2 when compared with collagen scaffolds + BMP2. BMP2 had little effect on osteoclast activity; however, less TRAP staining and osteoclast number was observed in the defects receiving collagen scaffolds when compared with BCP scaffolds. The release of BMP2 over time was rapidly released after 1 day on BCP scaffolds whereas a gradually release over time was observed for collagen scaffolds up to 14 days.
Conclusion
The osteoinductive properties of BMP2 may further be enhanced by its combination with a novel synthetically fabricated osteoinductive BCP scaffold. Future clinical testing is required to further assess these preliminary findings.
Histological and Histomorphometrical Evaluation of Postextractive Sites Grafted with Mg-Enriched Nano-Hydroxyapatite: A Randomized Controlled Trial Comparing 4 Versus 12 Months of Healing
Δευτέρα, 26 Οκτωβρίου 2015, 2:38:06 πμ | Luigi Canullo, Giovanni Wiel Marin, Marco Tallarico, Elena Canciani, Federica Musto, Claudia Dellavia
Abstract
Background
Tooth extraction generally results in an alveolar bone loss and structural changes in the overlying soft tissue. The amount of this relocation might jeopardize prosthetically driven implant placement. Thus, there is a high interest in techniques, materials and timing to minimizing tissue resorption, using postextraction ridge preservation procedures.
Purpose
To assess by histological techniques, the outcomes of a socket preservation technique at 4 or 12 months after treatment with a magnesium-enriched hydroxyapatite (Mg-e HA).
Materials and Methods
Postextraction site in 20 patients underwent ridge preservation procedure. Mg-e HA granules were mixed with blood and grafted into the socket. A bone specimen was collected from each site before implant placement after 4 or 12 months randomly. Each biopsy was processed for undecalcified histological analysis. All ground sections were observed under light and polarized microscope. A semi-quantitative analysis by mean of stereological method was performed to evaluate the average volume fractions of bone, biomaterial and medullary spaces, and the percentage of blood vessels for both timepoints. Nonparametric Mann–Whitney U test for unpaired data was used to detect eventual statistical differences between groups.
Results
Histologically, the biomaterial appeared surrounded by newly formed bone in both groups without inflammatory infiltrate. At 4 months, the remodeling process of collagen matrix was starting from the apical portion toward coronal direction and was more active around grafted particles. At 12 months, the alveolar socket was completely regenerated and filled with mineralized and well-organized bone tissue around the residual biomaterial particles. In both groups, vessels were present to supply tissues around the graft (at 4 months: 4.95% ± 2.49; at 12 months: 7.45% ± 2.57). Tissue fractions at 4 versus 12 months were respectively: 31.85% ± 6.99 versus 41.32% ± 9.37 for bone (p = .021), 40.82% ± 6.71 versus 26.28% ± 11.49 for residual Mg-e HA (p = .009), and 27.33% ± 7.72 versus 32.40% ± 9.87 for medullary spaces.
Conclusion
Data from the present study show that Mg-e HA allows the complete healing of the tissue. Additionally, graft material demonstrated to undergo significant resorption during the experimental time frame.
Transcrestal Sinus Lift Using Platelet Concentrates in Association to Short Implant Placement: A Retrospective Study of Augmented Bone Height Remodeling
Τρίτη, 20 Οκτωβρίου 2015, 11:38:43 πμ | Eduardo Anitua, Javier Flores, Mohammad Hamdan Alkhraisat
Abstract
Background
No evidence has been reported yet about dimensional changes in maxillary sinuses grafted with autologous platelet concentrate.
Purpose
This study aimed to analyze the augmented height alterations around short implants (length ≤ 8.5 mm) placed after transcrestal sinus lift surgery in association with plasma rich in growth factors.
Materials and Methods
A retrospective design was used. Patients with atrophic posterior maxilla were treated by inserting short implants in combination with transalveolar maxillary sinus floor augmentation. Radiographic bone level alterations over time were assessed on panoramic radiographs.
Results
Transalveolar sinus augmentation was performed to place 41 implants in 26 patients with a residual bone height of 4.7 ± 1.3 mm. The alveolar bone height was increased by 3.7 ± 1.7 mm and 4.2 ± 2.0 mm after 12 ± 3 months and 35 ± 11 months of surgery, respectively, whereas the apical augmented height (beyond the implant) apex was stable around 34 implants during the follow-up. It was increasing around seven implants that were not covered by the endo-sinus augmented height at the 1-year follow-up.
Conclusions
Transalveolar sinus floor augmentation in association with plasma rich in growth factors and short implants resulted in a stable augmented height gain after 3 years follow-up. Atrophic posterior maxilla could be treated by transalveolar sinus lift in association with plasma rich in growth factors and the placement of short implants.
Follow-Up of the Sinus Membrane Elevation Technique for Maxillary Sinus Implants without the Use of Graft Material
Abstract
Background
There is a limited amount of studies evaluating long-term results of the sinus membrane elevation technique for bone formation around implants in the maxillary sinus floor without the use of bone graft material.
Purpose
To investigate the long-term results of this technique with regard to implant survival and bone gain in the maxillary sinus floor.
Materials and Methods
A retrospective study was conducted on patients who had undergone the surgical procedure from November 2001 to August 2008. Thirty-six patients with a total of 87 implants (ASTRA TECH Implant System™) in 53 sinuses were examined. After a submerged healing period of 6 months and at least 12 months of loading, the patients were examined clinically and radiologically. Implant stability was measured using resonance frequency analysis (RFA).
Results
The mean follow-up time was 4.6 years (range 1.5–7 years). Five implants were lost giving a survival rate of 94.3%.Subantral preoperative vertical bone levels were in the range of 1 to 10 mm. The average bone gain at the sinus floor was 6 mm. The 55 fixtures eligible for RFA displayed a mean implant stability quotient of 77 (range 56–85.5).
Conclusion
The present study illustrates the long-term reliability of the technique.
Clinical Bonding of Resin Nano Ceramic Restorations to Zirconia Abutments: A Case Series within a Randomized Clinical Trial
Δευτέρα, 12 Οκτωβρίου 2015, 10:51:46 πμ | Ulf Schepke, Henny JA Meijer, Karin M Vermeulen, Gerry M Raghoebar, Marco S Cune
Abstract
Background
New dental materials are introduced and promoted in the field without extensive clinical testing. Using those materials in a clinical setting might result in unacceptable early failure rates.
Purpose
The purpose of this paper was to analyze bonding of a new dental restorative material to either zirconia stock abutments or zirconia customized abutments.
Materials and Methods
Fifty participants seeking single implant treatment were included in a prospective study. Resin Nano Ceramic (RNC, Lava Ultimate, 3M ESPE, Seefeld, Germany) crowns were digitally manufactured and extraorally bonded to either a stock or a customized zirconia abutment (ZirDesign and ATLANTIS, DENTSPLY Implants, Mölndal, Sweden) by means of a resin composite cement (RelyX Ultimate in combination with Scotchbond Universal, 3M ESPE), strictly following the manufacturer's recommendations. The final restorations were screw-retained to the implants and followed during 12 months. Primary outcome parameter was uncompromised survival of the restoration, and secondary outcome parameter was mode of failure.
Results
No implants were lost. The uncompromised survival rate of the RNC crowns bonded to zirconia abutments after 1 year of clinical service was only 14% (n = 7). Catastrophic failure occurred in three cases (6%), whereas bonding failure between RNC crowns and zirconia abutments occurred in 80% of the cases (n = 40) within the first year of service. No statistical significant difference in uncompromised survival rate could be identified between abutment types (χ2 = 1.495, p = .209). Uncompromised survival rate after 1 year was highly significantly different (χ2 = 104.173, p < .001) from a reference standard, which was set at 95%.
Conclusion
RNC crowns luted to stock and customized zirconia implant abutments with the particular resin composite cement in this trial have a poor prognosis, regardless of the abutment type used.
Five-Year Results of a Randomized Controlled Trial Comparing Patients Rehabilitated with Immediately Loaded Maxillary Cross-Arch Fixed Dental Prosthesis Supported by Four or Six Implants Placed Using Guided Surgery
Πέμπτη, 8 Οκτωβρίου 2015, 4:34:44 πμ | Marco Tallarico, Silvio Mario Meloni, Luigi Canullo, Martina Caneva, Giovanni Polizzi
Abstract
Purpose
To compare the 5-year clinical and radiological outcomes of patients rehabilitated with four or six implants placed using guided surgery and immediate function concept.
Materials and Methods
Forty patients randomly received four (All-on-4) or six (All-on-6) immediately loaded implants, placed using guided surgery, to support a cross-arch fixed dental prosthesis. Outcome measures were survival rates of implants and prostheses, complications, peri-implant marginal bone loss, and periodontal parameters.
Results
No drop-out occurred. Seven implants failed at the 5-year follow-up examination: six in the All-on-6 group (5%) and one in the All-on-4 group (1.25%), with no statistically significant differences (p = .246). No prosthetic failure occurred. Both group experienced some technical and biologic complications with no statistically significant differences between groups (p = .501). All-on-4 treatment concept demonstrated a trend of more complications during the entire follow-up period. A trend of more implant failure was experienced for the All-on-6 treatment concept. Marginal bone loss (MBL) from baseline to the 5-year follow-up was not statistically different between All-on-4 (1.71 ± 0.42 mm) and All-on-6 (1.51 ± 0.36 mm) groups (p = .12). For periodontal parameters, there were no differences between groups (p > .05).
Conclusion
Both approaches may represent a predictable treatment option for the rehabilitation of complete edentulous patients in the medium term. Longer randomized controlled studies are needed to confirm these results.
Treatment of Peri-Implant Defects in the Rabbit's Tibia with Adipose or Bone Marrow-Derived Mesenchymal Stems Cells
Πέμπτη, 24 Σεπτεμβρίου 2015, 5:08:02 μμ | Özgür Erdogan, Nuttawut Supachawaroj, Kumpanart Soontornvipart, Pakpoom Kheolamai
Abstract
Background
Mesenchymal stem cell (MSC) treatment in conjunction with bone graft materials or space filler can be an alternative to autogenous bone grafts in the treatment of peri-implant bone defects.
Purpose
To evaluate the success of bone regeneration capacity of adipose-derived and bone marrow-derived MSCs for the treatment of peri-implant bone defects when applied with a beta-tricalcium phosphate/collagen-based scaffold.
Material and Methods
Forty implants were placed into the tibiae of 10 rabbits bilaterally. Surgical defects created around the implants were treated with one the following treatment modalities: 1) adipose-derived MSC transplanted scaffold + collagen membrane; 2) bone marrow-derived MSC transplanted scaffold + collagen membrane; 3) autogenous bone + collagen membrane; and 4) collagen membrane only. The bone regeneration capacity of each technique was determined by histomorphometry, micro-CT, and measuring the implant stability by resonance frequency analysis.
Results
One limb of one rabbit was excluded because of fracture, and another limb was excluded because of infection. All parameters on 36 implants revealed that both sources of MSC can form equivalently new bone that is comparable with autogenous bone. The defects treated with membrane only had significantly less bone formation compared with other groups.
Conclusion
Both adipose-derived and bone marrow-derived MSC treatments are feasible alternatives to autogenous bone grafts in the treatment of peri-implant osseos defects.
Early Implant Failures Related to Individual Surgeons: An Analysis Covering 11,074 Operations Performed during 28 Years
Πέμπτη, 24 Σεπτεμβρίου 2015, 12:59:56 μμ | Torsten Jemt, Malin Olsson, Franck Renouard, Victoria Stenport, Bertil Friberg
Abstract
Background
Compared with knowledge on patient and implant component factors, little knowledge is available on surgeons' role in early implant failures.
Purpose
To report incidence of early implant failures related to total number of operations performed by individual surgeons.
Materials and Methods
Early implant failures (≤1 year of implant prosthesis function) were reported after a total of 11,074 implant operations at one specialist clinic during 28 years of surgery. Altogether, 8,808 individual patients were treated by 23 different dentists, of whom 21 surgeons were specialists in oral surgery or periodontology. Recorded failures were related to total numbers of performed operations per surgeon, followed by statistical comparisons (χ2) between surgeons with regard to type of treated jaw and implant surface.
Results
Altogether, 616 operations were recorded with early implant failures (5.6%), most often observed in edentulous upper jaws after placing implants with a turned surface (p < .05). Significant differences between surgeons, gender of surgeon, type of treated jaws by the surgeon, and implant surface used by the surgeon could be observed (p < .05).
Conclusions
Early implant failures are complex, multifactorial problems associated with many aspects in the surgical procedure. A stochastic variation of failures for individual surgeons could be observed over the years. Different levels of failure rate could be observed between the surgeons, occasionally reaching significant levels as a total or for different jaw situations (p < .05). The surgeons reduced their failure rates when using implants with moderately rough surfaces (p < .5), but the relationship of failure rate between the surgeons was maintained.
Dental Implants in Patients with Sjögren's Syndrome
Πέμπτη, 24 Σεπτεμβρίου 2015, 12:59:16 μμ | Anke Korfage, Gerry M Raghoebar, Suzanne Arends, Petra M Meiners, Anita Visser, Frans GM Kroese, Hendrika Bootsma, Arjan Vissink
Abstract
Background
Limited evidence is available for applying dental implants in Sjögren's syndrome (SS) patients.
Purpose
This study aims to retrospectively assess clinical outcome of implant therapy in a cohort of well-classified patients with SS.
Materials and Methods
All SS patients attending the University Medical Center Groningen for follow-up (n = 406) were asked whether they had implants. In SS patients with implants peri-implant health and implant survival was recorded and compared with data from matched healthy controls. Patients' symptoms, health-related quality of life, oral functioning, and satisfaction were assessed using validated questionnaires.
Results
Of the responding SS patients (n = 335), 21% was provided with implants. Of these 69 SS patients, 50 SS patients were willing to join our study. In SS patients, peri-implant health was reasonably good with minor marginal bone loss and a peri-implantitis prevalence of 14%, comparable with healthy controls. Implant survival was 97% (median follow-up 46 months) [IQR 26;73], and overall patients' satisfaction was high. Oral functioning correlated negatively with dryness, patients' satisfaction, and chewing ability in SS patients.
Conclusions
Implant therapy is common in our cohort of SS patients. In spite of shortcomings of our retrospective analysis, implants in SS patients seem to perform comparable with implants in healthy patients.
Clinical Fitting and Adjustment Time for Implant-Supported Crowns Comparing Digital and Conventional Workflows
Abstract
Purpose
The aim of this prospective cohort study was to investigate clinical and laboratory performance of implant-supported reconstructions comparing the digital to the conventional workflow.
Materials and Methods
Twenty study participants were treated in a cross-over design for single-tooth replacement in posterior sites, each with a customized titanium abutment plus computer-assisted design and computer-assisted manufacturing (CAD/CAM)-zirconia-suprastructure (test: digital workflow; n = 20) and a standardized titanium abutment plus PFM-crown (control: conventional pathway; n = 20). Evaluation of the 40 reconstructions included: 1) feasibility of laboratory cross-mounting of each abutment-crown-connection, and 2) assessment of adaptation time for clinical adjustments of interproximal and occlusal surfaces. Statistical analyses were performed using the exact Wilcoxon rank sum tests.
Results
Laboratory cross-mounting was feasible for three reconstruction pairings revealing a 15% vice versa transfer success rate. All implant crowns could be provided successfully within two clinical appointments, independently of the workflow used. The mean clinical adjustment time was significantly lower (p < .001) for test reconstructions from the digital workflow with 2.2 min (standard deviation [SD] ± 2.1) compared with the ones from the conventional pathway with 6.0 min (SD ± 3.9).
Conclusions
The digital workflow was almost threefold more efficient than the established conventional pathway for fixed implant-supported crowns. Clinical fitting could be predictably achieved with no or minor adjustments within the digital process of intraoral scanning plus CAD/CAM technology.
Osseointegration of Zirconia in the Presence of Multinucleated Giant Cells
Πέμπτη, 17 Σεπτεμβρίου 2015, 10:41:56 πμ | Vivianne Chappuis, Yeliz Cavusoglu, Reinhard Gruber, Ulrike Kuchler, Daniel Buser, Dieter D Bosshardt
Abstract
Background
Current strategies to reduce medical device-associated infections propose zirconia as a potential implant material which may limit bacterial adhesion. Because multinucleated giant cells (MNGCs) have been detected on these implant surfaces, concerns have been raised regarding tissue integration.
Purpose
The present study examined the presence of MNGCs and their subsequent effect upon tissue integration. Surface-modified implants made of yttria-stabilized (TZP) and alumina-toughened zirconia (ATZ) were compared with commercially pure titanium (Ti).
Materials and Methods
Seven miniature pigs received three implants on either side of the maxilla. After healing periods of 4 and 8 weeks, the tissue response at the implant surfaces was characterized according to three specific parameters: bone-to-implant contact (BIC), MNGC-to-implant contact (MIC), and the peri-implant bone density (BD).
Results
Despite being present on all tested implant surfaces, MNGCs were not associated with an inflammatory cell infiltrate or with fibrous encapsulation. MNGCs were less numerous on the Ti implants (range: 3.9–5.2%) compared with the ceramic implants (range: 17.6–30.3%, p < .0001). Even though the values of newly formed bone and pristine bone in direct contact with the implant surfaces were high at 4 weeks (tBIC: Ti = 82.3%, TZP = 64.3%, ATZ = 70%), a negative correlation was observed between the presence of MNGCs and newly formed bone at the implant surface (p < .001). Interestingly, the newly formed peri-implant bone density, defined as the percentage of new bone area inside the screw threads (nBD), was not diminished by the presence of MNGCs.
Conclusions
Differences in the presence of MNGCs and the BIC parameters between Ti and the ceramic implants appear to be a local cellular phenomenon which is restricted to the implant-bone marrow interface and do not affect the peri-implant bone formation. Factors triggering MNGC differentiation and their persistence in response to biomaterial surface need to be investigated in future studies.
Sinus Floor Augmentation Using Straumann® BoneCeramic™ and Bio-Oss® in a Split Mouth Design and Later Placement of Implants: A 5-Year Report from a Longitudinal Study
Abstract
Background
Straumann® BoneCeramic™ is a synthetic biphasic calcium phosphate (BCP) aimed for sinus floor augmentation. Long-term follow-up of implants placed in BCP after sinus augmentation is still missing.
Purpose
The primary aim of the study was to compare survival rates and marginal bone loss of Straumann SLActive implants placed in either BCP (test) or Bio-Oss® (DBB) (control) after sinus floor augmentation. The secondary aim was to calculate graft sinus height at different time points.
Materials and Methods
Bilateral sinus floor augmentation was performed in a split mouth model. Eleven patients (mean age 67 years) received 100% BCP on one side and 100% DBB on the contralateral side. After 8 months of graft healing, 62 Straumann SLActive implants were placed. After 5 years of functional loading (6 years after augmentation) of implants, marginal bone levels and grafted sinus height were measured, and implant survival and success rates were calculated.
Results
After 5 years of loading, all prosthetic constructions were in function although two implants were lost in each grafting material. The overall implant survival rate was 93.5% (91.7% for BCP, 91.3% for DBB, and 100% for residual bone). The success rates were 83.3% and 91.3% for BCP and DBB, respectively. There was no statistically significant difference in mean marginal bone level after 5 years between BCP (1.4 ± 1.2 mm) and DBB (1.0 ± 0.7 mm). Graft height reduction (GHR) after 6 years was limited to 6.6% for BCP and 5.8% for DBB.
Conclusion
In this limited RCT study, the choice of biomaterial used for sinus floor augmentation did not seem to have any impact on survival rates and marginal bone level of the placed implants after 5 years of functional loading and GHR was minimal.
Scientific Interests of 21st Century Clinical Oral Implant Research: Topical Trend Analysis
Παρασκευή, 28 Αυγούστου 2015, 9:54:08 πμ | Bernhard Pommer, Vesela Valkova, Ceeneena Ubaidha Maheen, Lukas Fürhauser, Xiaohui Rausch-Fan, Rudolf Seeman
Abstract
Background
Discrimination between ongoing and solved research questions may help to distinguish established dogmas from evidence-based implant dentistry.
Purpose
The purpose of this study was to investigate topics of interest in the field of oral implant science and evolving thematic trends in clinical studies during the last decade.
Materials and Methods
Electronic and manual searches of English literature were performed to identify clinical studies on oral implants. Out of 15,695 publications screened, 2,875 clinical investigations were included.
Results
Among the most prevalent topics were immediate loading (14.3%), bone substitutes (11.6%), lateral sinus grafting (10.7%), implant overdentures (10.5%), single-tooth implant crowns (8.8%), cross-arch implant bridges (8.0%), immediate implant placement (7.5%), implant surfaces (7.0%), simultaneous implant placement and augmentation (6.4%) as well as guided bone regeneration (5.3%). Significant increase of scientific interest was seen in immediate loading (+6.3%, p < .001), platform switching (+2.9%, p < 0.001), lateral sinus grafting (+2.3%, p = .024), flapless implant surgery (+2.2%, p < 0.001), and guided implant surgery (+1.9%, p = .011), while research on implant overdentures (−6.6%, p = .033) and tooth-to-implant connection (−2.5%, p = .010) was on the decline.
Conclusions
Literature coverage, since the beginning of the 21st century, has seen greater focus on surgical topics compared to prosthodontic issues (p = .005) while only few topics experienced decrease of interest indicating scientific consensus.
Two-Center Prospective, Randomized, Clinical, and Radiographic Study Comparing Osteotome Sinus Floor Elevation with or without Bone Graft and Simultaneous Implant Placement
Παρασκευή, 28 Αυγούστου 2015, 9:48:20 πμ | Aleksa Marković, Tijana Mišić, José Luís Calvo-Guirado, Rafael Arcesio Delgado-Ruíz, Bojan Janjić, Marcus Abboud
Abstract
Purpose
To evaluate stability and success rate of hydrophilic nanostructured implants placed via osteotome sinus floor elevation (OSFE) without grafting material or using β-tricalcium phosphate (β-TCP), deproteinized bovine bone (DBB), or their combination, and also to assess three-dimensional volumetric stability of endo-sinus bone gained in the aforementioned conditions.
Materials and Methods
OSFE with simultaneous implant placement (10-mm long SLActive-BL®, Straumann, Basel, Switzerland) was performed. Grafting materials were randomly allocated to implant sites, whereas one site was left without graft. Implant stability was measured by resonance frequency analysis over 6 months. Implant success was evaluated after 2 years of loading. Volume of new endo-sinus bone was calculated from CBCT images using 3D Slicer® software.
Results
A total of 180 implants were inserted into posterior maxilla of 45 patients with 6.59 ± 0.45 mm of residual bone height, and all remained successful after 2 years. Implant stability steadily increased during healing, without significant difference between groups (p = .658). After 2 years, endo-sinus bone significantly shrank (p < .001) in all groups (DBB:66.34%; β-TCP:61.44%; new bone formed from coagulum: 53.02%; β-TCP + DBB:33.47%).
Conclusions
Endo-sinus bone gained after OSFE inevitably and significantly shrinks regardless of whether grafting material is applied or not. Grafting material offers no significant advantage to stability nor clinical success of hydrophilic and nanostructured implants placed simultaneously with OSFE.
A 1-Year Clinical and Radiographic Study on Hydrophilic Dental Implants Placed with and without Bone Augmentation Procedures
Abstract
Purpose
The aim of the present 1-year clinical and radiographic study was to evaluate a hydrophilic dental implant when used in everyday cases in one clinic. The purpose was also to compare augmented with nonaugmented sites.
Materials and Methods
The study group consisted of 50 consecutive patients treated with 159 dental implants (Proactive, Neoss Ltd, Harrogate, UK) in both mandibles and maxillae. Ninety-two implants were placed with adjunct bone augmentation procedures, whereas 40 implants were placed in augmented maxillary sinus sites. A two-stage procedure was used for 84 implants and a one-stage procedure for 47 implants. Twenty-eight implants were immediately loaded. Implant stability was measured with resonance frequency analysis (RFA) at placement and at prosthesis delivery. The patients were scheduled for checkups after 6 and 12 months in function with clinical and radiographic examinations. Marginal bone level measurements were performed in baseline and follow-up intraoral radiographs.
Results
Two implant failures in two patients were experienced after 1 year of loading, giving a survival rate of 98.7%. One implant in nonaugmented sites and one implant in conjunction with an augmentation procedure (sinus lift), giving a survival rate of 98.5% and 98.9% for healed and augmented sites, respectively (NS). RFA measurements showed 70.2 ± 9.5 ISQ at placement and 76.5 ± 5.9 ISQ (p ≤ 0.001) after a mean healing time of 5.6 ± 1.6 months. The marginal bone loss amounted to 0.7 ± 0.7 mm after 1 year of loading. Frequency distribution showed bone gain or less than 1 mm bone loss for the majority of implants (69.3%), whereas 25.7% showed 1.1 to 2 mm, 5.0% more than 2 mm and no implants more than 3 mm of bone loss.
Conclusions
The use of Neoss Proactive implants for prosthetic rehabilitation of consecutive patients resulted in predictable clinical and radiographic outcomes after 1 year of loading with no differences between augmented and nonaugmented sites.
Implants with an Oxidized Surface Placed Predominately in Soft Bone Quality and Subjected to Immediate Occlusal Loading: Results from an 11-Year Clinical Follow-Up
Abstract
Purpose
The purpose of this clinical follow-up was to document the 11-year outcome of implants with a moderately rough oxidized surface subjected to immediate occlusal loading.
Materials and Methods
Twenty-six of 38 patients enrolled in a 5-year prospective study were available for this follow-up analysis, with 33 restorations supported by 66 slightly tapered implants (Brånemark System MkIV, Nobel Biocare, Gothenburg, Sweden). The majority of implants were placed in posterior regions (88%) and into soft bone (76%). Parameters included cumulative survival rate (CSR), radiographic marginal bone level, bleeding on probing (BOP), intrasulcular counts of perio-pathogenic markers (DNA probes), and total bacterial load (TBL).
Results
The CSR was 97.1% at 11.2 years mean follow-up. Mean marginal bone remodeling was 0.47 mm (SD 1.09, n = 65) from 1 year postplacement to 11-year follow-up. BOP was absent at most sites (63.6%). No statistically significant differences in TBL or perio-pathogenic marker species were observed at implants and teeth.
Conclusion
The results of the present follow-up show high long-term survival, stable marginal bone levels, and soft tissue outcomes of oxidized surface implants placed predominately in posterior regions and soft bone. The quantity and quality of intrasulcular microbiota were comparable at implants and teeth.
Decementation Rates and the Peri-Implant Tissue Status of Implant-Supported Fixed Restorations Retained via Zinc Oxide Cement: A Retrospective 10–23-Year Study
Τετάρτη, 12 Αυγούστου 2015, 1:53:11 μμ | Johan P Woelber, Petra Ratka-Krueger, Kirstin Vach, Eberhard Frisch
Abstract
Background
Long-term data on clinical outcomes of restorations attached to implants via zinc oxide (ZnO) cement have been sparse.
Purpose
The purpose of this study was to retrospectively investigate decementation rates and peri-implant tissue status of implant-supported fixed restorations retained by ZnO cement.
Materials and Methods
Between 1989 and 2003, 63 partially edentulous patients received 93 implants. Of these, 27 patients received 36 screwed single crowns (SC) and served as a control (C group). The other 36 patients had their restorations cemented using ZnO cement. They were subdivided into a SC group and a fixed dental prosthesis (FDP) group. After between 10 and 23 years (mean: 13.22 ± 3.21), all decementation events and peri-implant soft tissue status were evaluated using patient records.
Results
Decementation was assessed in 57 implants supporting 30 SCs and 16 FDPs. Five cases of decementation (8.77%) were recorded after a mean of 9.27 ± 7.05 years (range: 4.81–21.79). In the control group of vertically screwed SCs, five events of screw loosening (13.89%) were recorded in five patients (18.52%) after a mean of 5.84 ± 5.96 years (range: 0.56–15.05) within a 14.30 year observation period. No cases of peri-implantitis were observed in any group. The mean values of periodontal probing depths and bleeding on probing (BOP+) were 3.74 mm and 31.58%, respectively, for ZnO-cemented restorations, versus 3.76 mm and 25%, respectively, for the C group. No significant correlations regarding technical/biologic complications between the groups were detected.
Conclusions
Within the limitations of this study, we conclude that the use of ZnO cement provides sufficient retention of implant-supported fixed restorations over long periods without biologic complications in form of peri-implantitis.
Sequential Healing at Implants with Different Configuration and Modified Surfaces: An Experimental Study in the Dog
Τετάρτη, 12 Αυγούστου 2015, 1:16:40 μμ | Michael T. Schweikert, Daniele Botticelli, Luca Sbricoli, Antonio Antunes, Vittorio Favero, Luiz A. Salata
Abstract
Purpose
To evaluate the peri-implant soft and hard tissue adaptation at implants with different modified surfaces and configurations.
Materials and Methods
Six Beagle dogs were used. Mandibular premolars and first molars were extracted bilaterally. After 3 months, full-thickness flaps were elevated, and two different types of trans-mucosal implants (ICX-Gold®, Medentis Medical GmbH, Dernau, Germany and SLActive®, Institute Straumann, Bern, Switzerland) and two different surfaces were randomly installed in the distal regions of one side of the mandible. Abutments were applied, and a nonsubmerged healing was allowed. After 1 month, the procedures were performed in the other side of the mandible, and after a further month, the animals were sacrificed, biopsies were collected, and ground sections prepared for histological examination.
Results
Similar results in marginal bone and soft tissues dimensions were observed after 1 month of healing at the two implant systems used, and no major changes could be observed after 2 months of healing. After 1 month, the percentage of new bone was 69.0% and 68.8% at ICX-Gold and SLActive surfaces, respectively. After 2 months, the percentage of new bone was 67.8% and 71.9% at ICX-Gold Medentis and SLActive surfaces, respectively. No statistically significant differences in osseointegration were found.
Conclusion
The two implant systems used resulted in similar osseointegration after 1 and 2 months of healing.
Adhesion Properties of Human Oral Epithelial-Derived Cells to Zirconia
Πέμπτη, 6 Αυγούστου 2015, 5:41:55 πμ | Eijiro Okabe, Yuichi Ishihara, Takeshi Kikuchi, Ario Izawa, Shuichiro Kobayashi, Hisashi Goto, Yosuke Kamiya, Keisuke Sasaki, Seiji Ban, Toshihide Noguchi, Tatsushi Kawai, Akio Mitani
Abstract
Background
Few studies have examined epithelial attachment to zirconia and the proliferative ability of epithelial cells on zirconia surfaces.
Purpose
To evaluate the adhesion properties of zirconia materials for epithelial cell attachment and compare this with titanium and alumina.
Materials and Methods
Human oral epithelial cells were cultured on smooth-surfaced specimens of commercially pure titanium (cpTi), ceria-stabilized zirconia/alumina nano-composite (P-NANOZR), yttria-stabilized zirconia (Cercon), and alumina oxide (inCoris AL). The cell morphology, the cell viability and mRNA of integrin β4, laminin γ2, catenin δ2, and E-cadherin were evaluated by SEM, Cell-Counting Kit-8, and real-time PCR, respectively.
Results
Morphology of cells attached to specimens was similar among all groups. The viable cell numbers on Cercon and inCoris AL after 24 hours culture were significantly higher than for cpTi. Integrin β4, laminin γ2, and catenin δ2 mRNA expression was not different among all groups. However, at 3 and 24 hours after incubation, E-cadherin mRNA expression in the P-NANOZR group was significantly higher than for cpTi.
Conclusion
Zirconia may support binding of epithelial cells through hemidesmosomes comparable with titanium. Furthermore, P-NANOZR may impart resistance to exogenous stimuli through strong intercellular contacts with peri-implant mucosal cells when used as an abutment and implant superstructure.
A Prospective Longitudinal Study on Implant Prosthetic Rehabilitation in Controlled HIV-Positive Patients with 1-Year Follow-Up: The Role of CD4+ Level, Smoking Habits, and Oral Hygiene
Τρίτη, 4 Αυγούστου 2015, 10:59:11 πμ | Enrico F. Gherlone, Paolo Capparé, Simona Tecco, Elisabetta Polizzi, Giuseppe Pantaleo, Giorgio Gastaldi, Maria Gabriella Grusovin
Abstract
Background
A recent study showed that implant-prosthetic rehabilitation in well-controlled HIV patients gave slightly worse results than in an healthy population, and failures were all linked to infection.
Purpose
The aim of this study was to examine the associations between the success of implant-prosthetic treatment and systemic CD4+ level, smoking habits, and oral hygiene.
Materials and Methods
This mono-centric study included HIV patients with a stable disease and good oral hygiene requiring implant rehabilitation. Each patient received at least one dental implant. Prosthesis were delivered after 90 days in the upper jaw and 60 days in the lower jaw. Primary outcome measures were prosthetic failures, implant failures, peri-implant marginal bone level changes, and biological complications (peri-implantitis, pus, pain, paresthesia). The possible association with CD4 count, smoking habits, and oral hygiene was analyzed.
Results
Sixty-eight patients received 194 implants, and 66 patients (190 implants) were followed for 1 year. No significant associations were found between CD4+ count, oral hygiene-associated variables, and any of the outcome measures. If compared with nonsmoking/light smoking patients, patients who smoked >10 cigarettes/day suffered a statistically significant greater number of implant failures (p ≤ .005), presented a comparatively higher number of peri-implantitis (p < .001), as well as a higher frequency of pus (p ≤ .007), and reported pain (p ≤ .009).
Conclusion
Within the limitation of the present study, placement of dental implants in HIV-positive patients with stable disease seems a reasonable treatment option, regardless of CD4+ cell count, provided that they are in a normal range. Oral hygiene variables were not influent in this group of patient following recall appointments, while HIV-positive heavy smokers (>10 cigarettes/day) demonstrated an increased risk of early implant failure, peri-implantitis, episodes of pus, and self-reported pain.
Platform-Switching for Cemented Versus Screwed Fixed Dental Prostheses: Reliability and Failure Modes: An In Vitro Study
Τρίτη, 4 Αυγούστου 2015, 9:04:55 πμ | Rodolfo Brunieira Anchieta, Lucas Silveira Machado, Ronaldo Hirata, Estevam Augusto Bonfante, Paulo G. Coelho
Abstract
Purpose
The aim of this study was to evaluate the probability of survival of cemented and screwed three-unit implant-supported fixed dental prostheses (ISFDP) using different implant-abutment horizontal matching configurations (regular vs switching platforms).
Methods
One hundred and sixty-eight implants with internal hexagon connection (4 mm diameter, 10 mm length, Emfils; Colosso Evolution System, Itú, SP, Brazil) were selected for this study according to the horizontal implant-abutment matching configuration (regular or switching) and retention method and divided in four groups (n = 21 per group) as follows: 1) regular platform cemented (IRC); 2) or screw-retained (IRS); 3) switched-platform cemented (ISC); or 4) screw-retained (ISS). Regular and platform-switched abutments (Colosso evolution, 4 mm and 3.3 mm, respectively) were torqued, and 84 three-unit metal bridges were fabricated (first molar pontic). Implants were embedded in polymethyl-methacrylate resin and subjected to step-stress accelerated life testing in water. Weibull distribution was used to determine the probability of survival for a mission of 100,000 cycles at 400 N (90% two-sided confidence intervals). Polarized light and scanning electron microscopes were used for fractographic analysis.
Results
The β values of 0.50, 1.19, 1.25, and 1.95 for groups IRC, IRS, ISC, and ISS respectively, indicated that fatigue accelerated the failure for all groups, except IRC. The cement-retained groups presented significantly higher probability of survival (IRC – 98%, ISC – 59%) than screw-retained groups (IRS – 23% and ISS – 0%). Screw-retained FDPs exclusively failed by abutment-screw fractures, whereas cement-retained presented implant/screw/abutment fractures.
Conclusions
The probability of survival of cement-retained ISFDP was higher than screw-retained, irrespective of implant-abutment horizontal configuration.
Salivary Concentration of Oxidative Stress Biomarkers in a Group of Patients with Peri-Implantitis: A Transversal Study
Παρασκευή, 31 Ιουλίου 2015, 1:35:53 μμ | Mariano Sánchez-Siles, Javier Lucas-Azorin, Noemi Salazar-Sánchez, Luis Carbonell-Meseguer, Fabio Camacho-Alonso
Abstract
Purpose
The purpose of this study was to know if peri-implantitis causes an increase in the total salivary concentration of oxidative stress markers.
Materials and Methods
Seventy patients, 28 men and 42 women, 60 of them with dental implants, 30 of which had peri-implantitis and 30 were healthy. The remaining 10 were the control group: healthy subjects without implants. The average number of implants per patient was 4.70 ± 2.29 in the peri-implantitis group and 2 70 ± 2.11 in the control group. Periodontal/peri-implant variables were assessed, including bleeding index, gingival index, clinical attachment level, probing depth, presence of pockets larger than 4 and 6 mm, pain to percussion, suppuration, gingival hyperplasia or granuloma, crestal bone loss (both mesially and distally), evaluated through periapical radiography. Saliva samples from the 70 subjects were collected for measurement of malondialdehyde high performance liquid chromatography (HPLC) and myeloperoxidase (enzyme-linked immunosorbent assay analysis) concentrations.
Results
Implants affected with peri-implantitis had an average follow-up of 26.40 ± 7.97 months. 4.12% of implants with peri-implantitis had a painful response to percussion. 2.06% showed suppuration; 25.77% had granuloma. The mean crestal bone loss in implants wtih peri-implantitis was 3.78 ± 1.17 mm. Total salivary malondialdehyde concentration in the peri-implantitis group (0.52 ± 0.37 μM/l) was slightly higher than that in the group with healthy implants (0.40 ± 0.16 μM/l) and also slightly higher than that in the group of healthy patients without implants (0.41 ± 0.79 μM/l), although the difference was not statistically significant, p value = .442. Myeloperoxidase concentration was slightly higher in the peri-implantitis group (12.32 ± 2.17 ng/ml) than in the group with healthy implants (11.54 ± 2.80 ng/ml) and the group of healthy patients without implants (11.86 ± 2.67 ng/ml), without statistically significant differences, p value = .584.
Conclusions
The salivary concentration of oxidative stress markers in patients with peri-implantitis and without periodontitis is not higher than that found in healthy patients.
Comparing Two Diagnostic Procedures in Planning Dental Implants to Support a Mandibular Free-Ending Removable Partial Denture
Τρίτη, 14 Ιουλίου 2015, 4:38:47 μμ | Charlotte Jensen, Gerry M. Raghoebar, Henny J.A. Meijer, Rutger Schepers, Marco S. Cune
Abstract
Background
The use of a cone beam computed tomography (CBCT) for the preoperative implant planning is increasing. A clear guideline is needed in which cases of CBCT is essential.
Purpose
In this study, two imaging modalities (panoramic radiograph and CBCT) are compared in preoperative implant planning in the severely resorbed mandible and the influence on the observers assessments.
Materials and Methods
Thirty-four consecutive patients with bilateral edentulous regions in the mandible were included. The feasibility of implant placement in the premolar and molar region was judged by three observers on basis of casts either with a panoramic radiograph or a CBCT.Cohen's kappa, sensitivity and specificity rates, odds of agreement and disagreement as well as the odds ratios (ORs, ratio between odds of agreement and disagreement) were calculated per observer and overall for all observers assuming the majorities agreement as the prevailing opinion.
Results
Overall outcome for premolar region revealed true-positive and true-negative rates of 90% and 0%, respectively, with Cohen's kappa (κ) = −0.04. The ORs for the three observers varied between 2.6 and 158.8, with an overall OR = 76.For the molar region, overall true-positive and true-negative rates were 65% and 22% respectively, with Cohen's κ = 0.68, representing a reasonable amount of agreement. Sensitivity and specificity as well as the ORs for individual observers were fairly consistent with an overall OR = 43.
Conclusion
Implant placement in the resorbed posterior mandible can be well assessed with a cast in combination with a panoramic radiograph in the vast majority of the cases. Misclassification amounts to approximately 10% to 13%. In all cases of misclassification, a critical bone height, or an unclear course of the mandibular nerve or a knife edge ridge was present. In these cases, the use of a CBCT is justified.
Accelerated Osteogenic Differentiation and Bone Formation on Zirconia with Surface Grooves Created with Fiber Laser Irradiation
Τρίτη, 14 Ιουλίου 2015, 4:12:45 μμ | Yusuke Taniguchi, Kae Kakura, Katsuki Yamamoto, Hirofumi Kido, Jun Yamazaki
Abstract
Background
Modification of the surface topography of biomaterials is a critical factor for the proliferation and differentiation of osteoblasts. Elucidating the biological response to surface roughening is necessary for clinical application of zirconia implants.
Purpose
To investigate the effects of fiber laser-induced zirconia surface roughening on cultured osteoblast-like cell morphology, proliferation, differentiation, and calcification, and on in vivo bone formation.
Materials and Methods
Sixty-six machine-surfaced yttria-tetragonal zirconia polycrystal plates (S-Zr) and 16 machine-surfaced implants were used as controls. We prepared 66 rough plates (R-Zr) and 16 rough implants by surface treatment using a fiber laser.
Results
MC3T3-E1 cells spread well in all directions on S-Zr, whereas elongated cells with poorly organized actin stress fibers were observed on R-Zr. Cell proliferation was significantly greater on R-Zr than on S-Zr. The Runx2 mRNA level increased time dependently in osteogenic culture condition. Alkaline phosphatase activity and osteocalcin mRNA levels were higher on R-Zr compared with S-Zr. Alizarin red S staining revealed greater calcification on R-Zr than on S-Zr. Laser treatment of zirconia implant bodies placed in rat tibiae increased the bone-implant contact ratio and removal torque considerably.
Conclusions
Our results suggest that fiber laser irradiation produces adequate surface roughening of zirconia ceramics to support osseointegration.
Intraoperative Measurement of the Distance from the Bottom of Osteotomy to the Mandibular Canal Using a Novel Ultrasonic Device
Πέμπτη, 2 Ιουλίου 2015, 8:51:36 πμ | Hadar Zigdon-Giladi, Michael Saminsky, Rina Elimelech, Eli E. Machtei
Abstract
Background
In our previous study, we found that a novel ultrasound (US) device may serve as a useful intraoperative tool to measure the distance from osteotomy to the inferior alveolar canal (IAC).
Purpose
To validate our previous results in a larger group of osteotomies in the posterior mandible.
Methods
During dental implant placement surgery, osteotomies were created using a standardized 2-mm-diameter pilot drill. The distance from the bottom of the osteotome to the IAC was assessed using an ultrasonic device and compared with a standard panoramic radiograph used to measure the same residual distance. The total distance from the crestal bone to the IAC was measured on a preoperative computed tomography (CT) and compared with total US measurements by summing the drill depth with residual depth measurements.
Results
Mean radiographic and US residual distances were 5.19 ± 1.95 mm, 5.01 ± 1.82 mm, p = 0.79 respectively. These measurements presented strong positive correlations (r = 0.61, p = .01). Mean total CT distance was 13.48 ± 2.66 mm; mean total US calculation was 13.69 ± 2.51 mm. No significant difference was found (p > .05).
Conclusions
The results support our previous pilot study and confirm that the tested US device identifies the IAC and measures the distance from the osteotomy to the roof of the mandibular canal.
The Effects of Alveolar Ridge Preservation: A Meta-Analysis
Τετάρτη, 1 Ιουλίου 2015, 1:17:07 μμ | Maximillian Willenbacher, Bilal Al-Nawas, Manfred Berres, Peer W Kämmerer, Eik Schiegnitz
Abstract
Purpose
The aim of this article was to analyze the horizontal, vertical, and histological effects of alveolar ridge preservation (ARP) versus the ones of unassisted socket healing, in the format of an up-to-date review and meta-analysis.
Materials and Methods
An extensive electronic search in the electronic databases of the National Library of Medicine was conducted for articles published up to June 2014 to identify literature presenting data on the topic of ARP. Only randomized controlled trials, controlled clinical trials, and prospective trials were included for meta-analysis.
Results
After screening 903 abstracts from the electronic database, we included 64 studies in qualitative and 18 in quantitative synthesis. Quality assessment characterized a medium risk of bias for the included literature. The meta-analysis showed a mean difference between test and control groups of approximately 1.31 to 1.54 mm in bucco-oral bone width and 0.91 to 1.12 mm in bone height. Additionally, the intergroup difference in percentage of vital bone was assessed to be inconclusive across the included studies. Implants could be inserted into the determined position without further augmentation in 90.1% of the experimental sites, while this was the case in only 79.2% of the control sockets.
Conclusions
Resorption of the alveolar ridge cannot be totally stopped by ARP, while it still can be prevented compared with unassisted healing. No reliable predictions on the histological effects could be made due to limited data. Further on, no recommendation for a specific technique of ARP could be made. In conclusion, there is still need for ongoing research on the topic, even though the lower percentage of implant sites that needed additional augmentation in test sockets seemed to bring a patient benefit.
The Occurrence Rate and Diameter of Arteries Traveling Near the Mandible and an Assessment of the Relative Hemorrhage Risk in Implant Surgery
Abstract
Background
Bleeding in the floor of the mouth during implant surgery is attributed to arterial injuries in the sublingual space.
Purpose
This study aimed to assess the relative hemorrhage risk during implant surgery.
Materials and Methods
We investigated the occurrence rate and diameter of submental and sublingual arteries with special reference to their relationship with the course patterns of these arteries using 26 human cadavers.
Results
Three types of arteries were distinguished: main duct (MD), mucoperiosteal branches (MB), and cortical branches (CB). The occurrence rate of MB and CB was significantly high at the central incisor region in the upper part of the mylohyoid muscle, whereas the diameter of the MB and CB was significantly smaller than the occurrence rate of MD at the incisor regions. The occurrence rate of MD in the submental artery was significantly higher at the lateral incisor, canine, and premolar regions in the lower parts, whereas the occurrence rate of MD was significantly lower at the second and third molars in the upper parts.
Conclusion
The susceptibility of the submental artery to injury is suggested at the incisors, canine, premolars, and first molar regions during implant surgery.
Platelet-Rich Plasma: A Study of the Variables that May Influence Its Effect on Bone Regeneration
Τετάρτη, 1 Ιουλίου 2015, 8:04:16 πμ | Mª del Mar Jovani-Sancho, Chirag C Sheth, Mariano Marqués-Mateo, Miguel Puche-Torres
Abstract
Background
Currently, the use of platelet-rich plasma in bone regeneration is a real option, although more than one opinion has alerted us to the absence of clinical benefits.
Purpose
Analysis of the factors able to modify the characteristics of the platelet preparation obtained by Curasan, Plasma Rich in Growth Factors (PRGF), Platelet Concentrate Collection System (PCCS) and SmartPrep systems, relating them to the type of clinical application and the final bone regeneration achieved.
Materials and Methods
A search was conducted in PubMed using the keywords "platelet-rich plasma," "PRP," "platelet rich growth factors," and "oral bone regeneration." Four widely accepted protocols for the obtention of PRP (above) were analyzed. Any clinical studies with controls, using the four preparation protocols and with a 4 to 6 weeks follow-up period were compared. The protocols were also grouped according to the type of PRP application: PRP-alone, with bone, or with bone substitutes.
Results
Bone regeneration was not achieved in any of the cases using PRP obtained by Curasan and PCCS systems, whereas PRP obtained by SmartPrep achieved it only in one in three published cases and PRGF in one in six.
Conclusion
Based on the poor results observed in current literature, the use of PRP in oral surgery cannot be recommended.
Combined Treatment Effects Using Bioactive-Coated Implants and Ceramic Granulate in a Rabbit Femoral Condyle Model
Τετάρτη, 24 Ιουνίου 2015, 11:36:16 πμ | Reghunathan S. Preethanath, Palangadan Rajesh, Harikrishna Varma, Sukumaran Anil, John A. Jansen, Jeroen J.J.P. Beucken
Abstract
Background
Resolution of peri-implant defects resulting from implant placement in the freshly extracted site demands for a bone graft substitute that stimulates bone regeneration and hence facilitates implant integration. In view of this, the addition of silica to hydroxyapatite (HASi) could enhance the bioactive behavior of ceramic materials and implant surfaces coated with bioactive ceramics might benefit the interaction between bone and implant.
Purpose
To evaluate the bone response to implants coated with hydroxyapatite-silica (HASi) or hydroxyapatite (HA) and either or not combined with HASi and HA ceramic bone substitute particles, respectively, on bone-to-implant contact (BIC) and bone formation using a rabbit femoral condyle implant model with a gap design.
Material and Methods
A total of 32 custom-made, titanium implants (Ti: diameter 5 mm, length 8 mm) with two-sided gaps were fabricated and coated with either HASi or HA using pulsed laser deposition (PLD). The implants were installed bilaterally in the femoral condyles of 16 New Zealand white rabbits. According to a randomization protocol, one gap of HASi-coated and HA-coated implants was filled with HASi particles and HA particles, respectively, and the other gap was left empty. After an implantation period of 8 weeks, the retrieved specimens were analyzed via histology and histomorphometry (i.e., bone to implant contact [BIC] and bone volume [BV]).
Results
The BIC and BV around the implants were analysed for HASi- and HA-coated implants with and without the use of HASi and HA bone substitute material. Comparison of HASi- and HA-coated implants showed similar BIC for HASi- (55.7 + 11.0) and HA-coated implants (50.3 + 19.7). When coated implants were combined with bone substitute materials, HASi-coated and particle-filled implants showed higher BIC (64.3 ± 6.8%) compared with HA-coated and HA-filled implants (54.5 ± 10.9%). Similarly, the BV within the region of interest showed significantly higher values for the HASi-coated and HASi-filled implants (21.1 ± 1.7%) compared with HA-coated and HA-filled implants (12.8 ± 4.9%).
Conclusions and Clinical Implications
Within the limitations of this study, it can be concluded that silicon substitution in HA favors bone regeneration compared with HA, especially when used as bone substitute material. Further studies using different healing periods will elucidate the resorption pattern of HASi granules in comparison with HA.
Dental Implants in an Aged Population: Evaluation of Periodontal Health, Bone Loss, Implant Survival, and Quality of Life
Τετάρτη, 17 Ιουνίου 2015, 10:54:55 πμ | William Becker, Philippe Hujoel, Burton E. Becker, Peter Wohrle
Abstract
Purpose
To evaluate aged partially and fully edentulous patients who received dental implants and were maintained over time. Further, to determine how the partially and edentulous ageing populations (65 and above) with dental implants maintain bone levels, proper oral hygiene, and perceive benefits of dental implants.
Materials and Methods
Since 1995, patients receiving dental implants have been prospectively entered into an Access-based computerized program (Triton Tacking System). Patient demographics (age, sex), bone quality, quantity, implant location, and type of surgery have been continuously entered into the database. The database was queried for patients receiving implants (first stage) between 66 and 93 years of age. Thirty-one patients were within this age group. Twenty-five patients returned to the clinic for periodontal and dental implant evaluation. The Periodontal Index was used to evaluate selected teeth in terms of probing depth, bleeding on probing, plaque accumulation, and mobility. Using NIH Image J, radiographs taken at second stage and last examination were measured for changes in interproximal bone levels. Once identified, each patient anomalously filled out an abbreviated quality of health life form. Due to small sample size, descriptive statistics were used to compare clinical findings.
Results
Fifteen males ranging from 78 to 84 (mean age 84 years) years and 16 females from 66 to 93 (mean age 83 years) (age range 66–93) were contacted by phone or mail and asked to return to our office for a re-examination. For this group, the first dental implants were placed in 1996 (n = initial two implants) and continuously recorded through 2013 (n = last seven implants). Thirty-one patients received a total of 84 implants. Two patients were edentulous, and the remaining were partially edentulous. Four implants were lost. Between implant placement and 6- to 7-year interval, 13 patients with 40 implants had a cumulative survival rate of 94.6%. Of the original group (n = 33), three were deceased, two were in nursing homes, and three could not be located.
Conclusions
Aged patients receiving dental implants had excellent implant survival rates, low periodontal disease index scores with minimal changes in interproximal bone levels. Results from this study indicate that patients with advanced age, in reasonably good health, have excellent implant survival rates, excellent quality of life scores, and can be maintained in good oral health.
Antimicrobial Effect of a Single Dose of Amoxicillin on the Oral Microbiota
Παρασκευή, 5 Ιουνίου 2015, 2:15:40 μμ | Cecilia Larsson Wexell, Henrik Ryberg, Wivi-Anne Sjöberg Andersson, Susanne Blomqvist, Pieter Colin, Jan Van Bocxlaer, Gunnar Dahlén
Abstract
Purpose
Amoxicillin is commonly used in oral surgery for antimicrobial prophylaxis against surgical-site infection and bacteremia because of its effect on oral streptococci. The aim of this study was to determine whether amoxicillin reaches the break-point concentrations in saliva and has any effect on the salivary microbiota, colonizing bacteria on mucosal membranes and on the gingival crevice after a single dose of amoxicillin.
Material and Methods
Twenty subjects received 2 g of amoxicillin, per os. The facultative and strictly anaerobic microflora, as well as the streptococcal microflora specifically, were followed from baseline and after 1, 4, and 24 hours. Samples were taken for microbial analysis from saliva, the dorsum of the tongue, and the gingival crevice, and were inoculated and cultured. Plasma samples and saliva samples were analyzed for amoxicillin concentrations (free and protein bound) using liquid chromatography and mass-spectrometry.
Results
Amoxicillin was detected in concentrations over the break-point (>2 μg/mL) of amoxicillin in plasma after 1 and 4 hours but not after 24 hours. The dose had a significant effect on the streptococci in the gingival crevice.
Conclusion
A single dose given as prophylaxis to prevent a surgical-site infection results in a significant reducing effect on the oral streptococcal microflora in the gingival crevice and may have an impact on bacteria spreading into tissues and the bacteremia of streptococci.
The Effect of Insertion Torque on the Clinical Outcome of Single Implants: A Randomized Clinical Trial
Παρασκευή, 5 Ιουνίου 2015, 8:38:59 πμ | Antonio Barone, Fortunato Alfonsi, Giacomo Derchi, Paolo Tonelli, Paolo Toti, Saverio Marchionni, Ugo Covani
Abstract
Background
The insertion torque value has been extensively used as an indicator for implant primary stability, which is considered a determining parameter for the implants success.
Purpose
The primary goal of the present randomized clinical trial was to evaluate and compare the clinical outcome for implants placed with high insertion torque (between 50 Ncm and 100 Ncm) and regular insertion torque (within 50 Ncm) in healed ridges.
Materials and Methods
Partially edentulous patients, missing one or more mandibular or maxillary teeth, having an adequate amount of bone, requiring implant placement, were randomized to receive Blossom CT implants with regular insertion torque (<50 Ncm) or CT implants with high insertion torque (≥50 Ncm). Implants were left to heal submerged for 3 months. Implants were restored with individualized abutments and cemented metal-ceramic crowns. Acquired measurements were: insertion torque values (IT), thickness of buccal bone plate after implant osteotomy preparation (BBT), marginal bone level (MBL), and facial soft tissue level (FST). All patients were followed 12 months after implant placement.
Results
One hundred sixteen implants were placed in one hundred sixteen patients and enrolled for the study. Fifty-eight implants were randomly allocated in regular-IT and high-IT groups with a mean insertion torque ranging from 20 Ncm to 50 Ncm and from 50 Ncm to 100 Ncm, respectively. Three implants failed, and another five implants showed at the 12-month evaluation a marginal bone loss (ΔMBL) greater than 1.5 mm, being considered unsuccessful.
Conclusions
The findings suggested that implants inserted with high-IT (≥50 Ncm) in healed bone ridges showed more peri-implant bone remodeling and buccal soft tissue recession than implants inserted with a regular-IT (<50 Ncm). Moreover, sites with a thick buccal bone wall (≥1 mm) – after implant osteotomy site preparation – seemed to be less prone to buccal soft tissue recession after 12 months than sites with a thin buccal bone wall (<1 mm).
Evaluation of the Surface Treatment on Bone Healing in a Transmucosal 1-mm Area of Implant Abutment: An Experimental Study in the Rabbit Tibia
Abstract
Purpose
The objective of the present study was to investigate the effect on bone tissue healing patterns in 1-mm area treated in the transmucosal surface of the abutment in the tibia of rabbits.
Materials and Methods
Forty-six abutments were divided into two groups: control group (CG) with 14 abutments with smooth surface and experimental group (EG) with 32 abutments presenting a 1-mm area of the transmucosal surface treated through sandblasting with microparticles of titanium oxide followed by acid etching. Five samples of each group were analyzed using an optical laser profilometer for surface roughness characterization. Thirty-six Morse taper implants (3.5 mm in diameter and 7 mm in length) were inserted 1.5 mm subcrestal into the tibiae of nine rabbits. The implants were removed after 8, 10, and 12 weeks for histological analysis. The histological slides were prepared and analyzed qualitatively in relation to the new bone at the interface bone-abutment and quantitatively, in relation to bone height from the base of the implant. These data were computed and statistically compared inside the groups using analysis of variance and the U-test between groups for same time.
Results
Both groups exhibited bone growth in the direction and over the surface of the abutments, with good healing. However, the EG group showed an increased height of bone formation in the crestal direction, and highly significant differences were observed (p < .001) between these measured values.
Conclusions
Under the limitations of the present study, histological follow-up at 8, 10, and 12 weeks showed that transmucosal 1-mm area of implant abutment with treatment of the surface facilitated the maintenance of bone height around the abutment compared with the same abutment with the totally smooth surface.
High-Resolution Three-Dimensional Computed Tomography Analysis of the Clinical Efficacy of Cultured Autogenous Periosteal Cells in Sinus Lift Bone Grafting
Πέμπτη, 28 Μαΐου 2015, 5:04:35 πμ | Shin Ogawa, Hideyuki Hoshina, Koh Nakata, Kazuho Yamada, Kohya Uematsu, Tomoyuki Kawase, Ritsuo Takagi, Masaki Nagata
Abstract
Background and Purpose
Sinus lift (SL) using cultured autogenous periosteal cells (CAPCs) combined with autogenous bone and platelet-rich plasma (PRP) was performed to evaluate the effect of cell administration on bone regeneration, by using high-resolution three-dimensional computed tomography (CT).
Materials and Methods
SL with autogenous bone and PRP plus CAPC [CAPC(+)SL] was performed in 23 patients. A piece of periosteum taken from the mandible was cultured in M199 medium with 10% fetal bovine serum (FBS) for 6 weeks. As control, 16 patients received SL with autogenous bone and PRP [CAPC(−)SL]. Three-dimensional CT imaging was performed before and 4 months and 1 year after SL, and stratification was performed based on CT numbers (HUs) corresponding to soft tissue and cancellous or cortical bone.
Results
The augmented bone in CAPC(+)SL revealed an increase in HUs corresponding to cancellous bone as well as a decrease in HUs corresponding to grafted cortical bone. In addition, HUs corresponding to cancellous bone in the graft bed were increased in CAPC(+)SL but were decreased in CAPC(−)SL. Insertion torque during implant placement was significantly higher in CAPC(+)SL.
Conclusion
By promoting bone anabolic activity both in augmented bone and graft bed, CAPCs are expected to aid primary fixation and osseointegration of implants in clinical applications.
Significance of the Immunohistochemical Expression of Bone Morphogenetic Protein-4 in Bone Maturation after Maxillary Sinus Grafting in Humans
Τρίτη, 12 Μαΐου 2015, 2:59:02 μμ | Laura Torrecillas-Martínez, Pablo Galindo-Moreno, Gustavo Ávila-Ortiz, Inmaculada Ortega-Oller, Alberto Monje, Pedro Hernández-Cortés, David Aguilar, Francisco O'Valle
Abstract
Background
Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-β (TGFβ) protein superfamily and are known to be involved in bone and cartilage formation. Within this family, BMP-4 is one of the most studied members. It has been shown to induce osteogenic differentiation of osteoblasts and osteoprogenitor cells in vitro, but the intimate processes in which this protein promotes and regulates osseous repair still remains unclear.
Purpose
To assess whether the native cellular immunohistochemical expression of BMP-4 correlates with the maturation of bone samples obtained at 6 months after maxillary sinus augmentation.
Materials and Methods
Histopathological and histomorphometrical analyses were performed in all the samples, which were obtained from a total of 58 patients. Immunohistochemical expression of BMP-4 was analyzed in 30 core biopsies obtained from maxillary sinuses grafted with a combination of anorganic bovine bone and autogenous cortical bone [1:1] (AB-group), and 18 biopsies from maxillary sinuses grafted solely with a cortico-cancellous particulate allograft (M-group), all of them after a 6-month healing period. Also, 10 biopsies of native pristine bone were obtained and used as control group (C-group).
Results
Mild to moderate immunohistochemical expression of native granular BMP-4 was present in 56.8% (31.0% AB-group, 22.4% M-group, and 3.4% C-group) (p = 0.000, chi-square) of the specimens analyzed. BMP-4 expression was primarily located in the cytoplasm of osteoblasts, osteoclasts, and epithelial cells of the schneiderian membrane. Whereas significant differences were observed in the proportion of mineralized tissue and cellularity between sinuses grafted with anorganic bovine bone, allograft, or nongrafted sinuses, there were no statistically significant differences in the cellular expression of BMP-4 among groups.
Conclusion
Our findings suggest that the native expression of BMP-4 appears to be associated with normal bone homeostasis and reparation in grafted and nongrafted maxillary sites.
Anatomical Considerations on the Alveolar Antral Artery as Related to the Sinus Augmentation Surgical Procedure
Abstract
Background
The alveolar antral artery (AAA) is a vascular structure that often passes through the area of lateral window opening during sinus augmentation and can reach dimensions that, if the vessel is severed, can represent a serious complication of the surgical procedure.
Purpose
With this narrative review, we aimed at summarizing the results obtained from all the studies that analyzed the variability in anatomical position and dimension of the AAA in order to give the clinician a reference when planning for a sinus augmentation surgery.
Materials and Methods
A search of available literature was conducted using electronic databases (PubMed and Medline) and manual searching.
Results
Detection rate of AAA on cone beam computerized tomography (CBCT) is variable and may depend upon the experience of the clinician. The course of the vessel is most frequently intraosseous, and its diameter, despite being smaller than 1 mm in most of the cases, can have a high incidence of diameters between 1 mm and 2 mm. Mean distances of the AAA from alveolar crest and sinus floor range from 11.25 mm to 26.90 mm and 5.80 mm to 10.40 mm.
Conclusions
Anatomical variants of the AAA that may increase the risk of severe intraoperatory bleeding are frequent and must be detected by the clinician implementing the use of the CBCT.
Implant Prosthetic Rehabilitation in Controlled HIV-Positive Patients: A Prospective Longitudinal Study with 1-Year Follow-Up
Πέμπτη, 7 Μαΐου 2015, 2:17:31 μμ | Enrico F. Gherlone, Paolo Capparé, Simona Tecco, Elisabetta Polizzi, Giuseppe Pantaleo, Giorgio Gastaldi, Maria Gabriella Grusovin
Abstract
Purpose
The clinical trial aimed to evaluate the survival of implant-prosthetic rehabilitation in controlled HIV-positive patients.
Materials and Methods
This mono-centric study included HIV patients with a stable disease, requiring implant rehabilitation, with good oral hygiene. Each patient received at least one dental implant. After 90 days in the upper jaw and 60 days in the lower jaw, the appropriate prosthesis was delivered.Primary outcome measures were prosthetic failures, implant failures, peri-implant marginal bone level changes (MBLCs), and biological complications (peri-implantitis, pus, pain, paresthesia). Data were recorded before the intervention (T0), and 6 (T1) and 12 months (T2) after.
Results
Implants were positioned in 68 patients (22 females and 46 males; 194 implants). Two dropouts occurred for exacerbation of the disease before the sixth month of follow-up, and 66 patients (with 190 implants) completed the study. Forty-eight patients (70.6%) received total removable dentures; 11 patients (16.2%) received partial prosthesis, and nine patients (13.2%) received single elements.Implant failure occurred in nine patients (15 fixtures out of 190). These were early implant failures due to primary infection (five fixtures out of 190: 2.6%) and to peri-implantitis (10 fixtures out of 190: 5.2%). Prosthetic failure was registered in two patients (3% of patients) due to the loss of all the fixtures. Pus and pain were observed in 4/7 and 3/7 patients with peri-implantitis, respectively. No fractures of fixtures or paresthesia were registered. At T2, the mean peri-implant MBLC was −1.19 ± 0.87 mm.
Conclusions
Within its limitations, the study showed that in a well-controlled population of HIV patients implant rehabilitation can be a suitable options with results slightly worse to those obtained in normal population. A higher incidence of peri implant infections in the first six months was present pointing to the need of a proper protocol for infection control.
Immediate Loading of Dental Implants in Edentulous Mandibles by Use of Locator® Attachments or Dolder® Bars: Two-Year Results from a Prospective Randomized Clinical Study
Πέμπτη, 7 Μαΐου 2015, 1:38:36 μμ | Stefanie Kappel, Nikolaos Nikitas Giannakopoulos, Lydia Eberhard, Peter Rammelsberg, Constantin Eiffler
Abstract
Purpose
The study aims to evaluate survival and incidence of complications for pairs of implants placed in the front region of edentulous mandibles and immediately loaded with either bar or Locator attachments.
Materials and Methods
Forty-six patients with edentulous mandibles (mean age 69.4 years at inclusion in the study; 73.9% male) received two implants in the interforaminal area of the symphysis. Dolder bar or Locator attachments, allocated randomly, were then attached immediately, and both clips and a framework were fastened to the denture by the dental technician within 72 hours.
Results
During the first 3 months of the 2-year period of observation, eight implants in five patients were lost, and were removed. Survival was 89.1% and 93.5% for the bar and Locator groups, respectively. During the entire period of observation, 38 prosthetic complications required aftercare. Five dentures had to be removed or reworked after implant failure, but no superstructure was lost or had to be remade for prosthetic reasons. Survival of the original dentures was 93.5% and 95.7% for the bar and Locator groups, respectively.
Conclusion
Within the limitations of this study, results from immediate loading of two implants in the edentulous mandible with either Locator or bar attachments hardly differed. Prosthetic complications and aftercare measures in the Locator group were frequent but easy to handle. Ease of repair and cleaning, in particular, might be reasons for choosing the single-attachment system.
Randomized Controlled Clinical Trial of All-Ceramic Single Tooth Implant Reconstructions Using Modified Zirconia Abutments: Radiographic and Prosthetic Results at 1 Year of Loading
Τετάρτη, 15 Απριλίου 2015, 11:15:31 πμ | Daniel S. Thoma, Francine Brandenberg, Vincent Fehmer, Dominik L.E. Büchi, Christoph H.F. Hämmerle, Irena Sailer
Abstract
Purpose
This study aims to test whether or not veneering of the submucosal part of zirconia abutments with pink dental ceramic affects radiographic and technical outcomes of implant-supported single crowns (ISSC).
Materials and Methods
Single tooth implants were randomly restored with either pink-veneered zirconia abutments (test; n = 10) or non-veneered zirconia abutments (control group; n = 10) and all-ceramic crowns. At baseline (crown insertion), and 6- and 12-month radiographic and technical evaluations were performed including standardized x-rays and modified United States Public Health Service criteria (technical). Survival and complication rates were assessed for implants and restorations. Robust linear mixed model analysis was performed to investigate the effect of group and time-point on radiographic outcomes.
Results
At 1 year, the survival rate for implants was 100% and 95% for ISSC. Most of the implants were placed subcrestally. Therefore, mean marginal bone levels decreased in both groups between implant insertion and baseline (p < .05), but then remained stable up to 1 year (test: 0.15 mm ± 0.42 mm; control 0.23 mm ± 0.63 mm) (p > .005). At 6 months, one minor chipping occurred in the test group. At 1 year, three crowns (control) exhibited occlusal roughness. In addition, one abutment fracture occurred (test). The differences between test and control group were not statistically significantly different for any of the evaluated outcome measures (p > .05).
Conclusions
Veneering of the submucosal part of zirconia abutments did not affect biological and technical outcomes of ISSCs. Technical complications of the reconstructions, however, were frequent, resulting in a rate of 75% of the crowns being complication free.
Health, Maintenance, and Recovery of Soft Tissues around Implants
Abstract
Background
The health of peri-implant soft tissues is one of the most important aspects of osseointegration necessary for the long-term survival of dental implants.
Purpose
To review the process of soft tissue healing around osseointegrated implants and discuss the maintenance requirements as well as the possible short-comings of peri-implant soft tissue integration.
Materials and Methods
Literature search on the process involved in osseointegration, soft tissue healing and currently available treatment modalities was performed and a brief description of each process was provided.
Results
The peri-implant interface has been shown to be less effective than natural teeth in resisting bacterial invasion because gingival fiber alignment and reduced vascular supply make it more vulnerable to subsequent peri-implant disease and future bone loss around implants. And we summarized common procedures which have been shown to be effective in preventing peri-implantitis disease progression as well as clinical techniques utilized to regenerate soft tissues with bone loss in advanced cases of peri-implantitis.
Conclusion
Due to the difference between peri-implant interface and natural teeth, clinicians and patients should pay more attention in the maintenance and recovery of soft tissues around implants.
The Influence of Tactile Perception on Classification of Bone Tissue at Dental Implant Insertion
Δευτέρα, 6 Απριλίου 2015, 10:02:42 πμ | Gláucia Kelly Silva Barbosa Linck, Geovane Miranda Ferreira, Rubelisa Cândido Gomes De Oliveira, Christina Lindh, Cláudio Rodrigues Leles, Rejane Faria Ribeiro-Rotta
Abstract
Background
Various ways of using the Lekholm and Zarb (L&Z) classification have added to the lack of scientific evidence of the effectiveness of this clinical method in the evaluation of implant treatment.
Purpose
The study aims to assess subjective jawbone classifications in patients referred for implant treatment, using L&Z classification with and without surgeon's hand perception at implant insertion. The association between bone type classifications and quantitative parameters of primary implant stability was also assessed.
Materials and Methods
One hundred thirty-five implants were inserted using conventional loading protocol. Three surgeons classified bone quality at implant sites using two methods: one based on periapical and panoramic images (modified L&Z) and one based on the same images associated with the surgeon's tactile perception during drilling (original L&Z). Peak insertion torque and implant stability quotient (ISQ) were recorded.
Results
The modified and original L&Z were strongly correlated (rho = 0.79; p < .001); Wilcoxon signed-rank test showed no significant difference in the distribution of bone type classification between pairs using the two methods (p = .538). Spearman correlation tested the association between primary stability parameters and bone type classifications (−0.34 to −0.57 [p < .001]).
Conclusions
Tactile surgical perception has a minor influence on rating of subjective bone type for dental implant treatment using the L&Z classification.
Maxillary Three-Implant Overdentures Opposing Mandibular Two-Implant Overdentures: 10-Year Surgical Outcomes of a Randomized Controlled Trial
Τετάρτη, 1 Απριλίου 2015, 9:09:00 πμ | Sunyoung Ma, Andrew Tawse-Smith, Rohana K. De Silva, Momen A. Atieh, Nabeel H. M. Alsabeeha, Alan G. T. Payne
Abstract
Background
The surgical placement of four maxillary implants for overdentures may not be obligatory when opposing mandibular two-implant overdentures.
Purpose
To determine 10-year surgical outcomes and implant success of three narrow diameter implants in edentulous maxillae with conventional loading.
Materials and Methods
Forty participants with mandibular two-implant overdentures were randomly allocated for surgery for maxillary overdentures. Using osteotomes, three implants of similar systems were placed with a one-stage procedure and 12-week loading with splinted and unsplinted prosthodontic designs. Marginal bone and stability measurements were done at surgery, 12 weeks, 1-, 2-, 5-, 7-, 10 years.
Results
One hundred seventeen implants were placed in 39 participants, with 35 being seen at 1 year; 29 at 2 years; 28 at 5 years; 26 at 7 years; and 23 (59%) at 10 years. Marginal bone loss was 1.35 mm between surgery and 12 weeks; 0.36 mm between 12 weeks and 1 year; 0.48 mm between 1 and 5 years; and 0.22 mm between 5 and 10 years. Implant stability quotients were 56.05, 57.54, 60.88, 58.80, 61.17 at surgery, 12 weeks, 1 year, 5 years, and 10 years. Four-field tables by implant showed success rates of 82% at 1 year; 69.2% at 2 years; 66.7% at 5 years; 61.5% at 7 years; 51.3% at 10 years. Data showed no differences between surgical technique, systems, or prosthodontic designs.
Conclusions
Surgical placement with osteotomes of three narrow diameter implants for maxillary overdentures, opposing mandibular two-implant overdentures, is an acceptable approach, subject to strict patient selection. Implant success is independent of prosthodontic design.
Comparative Evaluation of Changes in Brain Activity and Cognitive Function of Edentulous Patients, with Dentures and Two-Implant Supported Mandibular Overdenture-Pilot Study
Δευτέρα, 30 Μαρτίου 2015, 11:09:47 πμ | Fathima Banu R, Padmanabhan T. Veeravalli, Anand Kumar V
Abstract
Background
The relationship between brain and prosthesis was previously assessed either by improving denture function or in fixed implant retained, wherein brain function was assessed only after crown placement.
Purpose
To prospectively analyze the changes in brain activity and cognitive function of completely edentulous patients in edentulous state, with dentures and two-implant supported mandibular overdenture before and after loading, along with the effect of mastication in the change – a pilot study.
Materials and Method
Ten completely edentulous (CE) non-denture wearers were selected. The mandibular prosthesis was loaded with two 3.3 mm × 13 mm myriad snap fit implants. To assess the brain activity and cognitive function, Electroencephalogram (Neurofax EEG 1000 Ver 05–90, Nihon Kohden corporation, Tokyo, Japan) and Mini-Mental State Examination (MMSE) questionnaire, respectively, were taken during the process of rehabilitation. EEG assessment was analyzed using Matlab 2011A 7.9 signal processing tool box. The results were statistically analyzed with SPSS 17.0 version using Wilcoxon signed rank and Friedman test
Results
Amplitude, power of alpha waves and cognitive scores increased gradually with highest mean rank for implant supported overdenture (IOD). The bivariate analysis between two groups showed there was significant difference between all the groups (p < 0.05) except for groups CE-I (completely edentulous – implant placement) and CD- I (complete denture insertion – implant placement) in amplitude of alpha waves while in group CD-I with respect to power of alpha waves. MMSE revealed the mean of cognitive scores in Complete Edentulous was 17.40, Complete Denture was 18.30 and finally with Implant Overdenture was 23.80.
Conclusion
The present study has enlightened the significance of two implant supported mandibular overdenture in improving the mental state of an individual and that the enhancement was due to functional improvement with prosthesis when loaded with implants and not due to mere existence of implant without any function.
Investigation of a Novel PLGA/CaP Scaffold in the Healing of Tooth Extraction Sockets to Alveolar Bone Preservation in Humans
Τετάρτη, 25 Μαρτίου 2015, 2:09:27 μμ | Ana Claudia Araujo-Pires, Vanessa Cristina Mendes, Osny Ferreira-Junior, Paulo Sérgio Perri Carvalho, Limin Guan, John Edward Davies
Abstract
Background
It is expected that 40% to 60% of initial alveolar bone volume will be lost up to 6 months after tooth extraction. OsteoScafTM (TRT, Toronto, ON, Canada) (poly (DL-lactide-co-glycololide/calcium phosphate [PLGA/CaP] scaffold) is a novel bone substitute material and represents a promising alternative for maintaining alveolar bone integrity in this clinical scenario.
Purpose
Here it was hypothesized that OsteoScaf would reduce alveolar bone lost after tooth extraction in patient, acting as a clot-retention device.
Material and Methods
A total of 10 patients (32 sockets) were included in the study, of which 16 sockets were grafted with OsteoScaf and 16 were used as control (coagulum alone). Cone beam computed tomography (CBCT) was performed both immediately following extraction and also at 120 days postoperatively, at which time biopsy samples were also harvested for histological analyses.
Results
Quantitative analysis of CBCT showed less bone resorption in the OsteoScaf groups, being 10.5% to 14.4% less bone lost in the center of the socket, 15.4% in the buccal region, and 12.6% in the palatal. Qualitative histological analysis showed new bone tissue in direct apposition to the scaffold – demonstrating its osteoconductive nature.
Conclusion
OsteoScaf diminished the expected bone lost during the postextraction remodeling of the alveolar bone ridge at 120 days postextraction.
Maxillary Four Implant-retained Overdentures via Locator® Attachment: Intermediate-term Results from a Retrospective Study
Δευτέρα, 23 Μαρτίου 2015, 8:29:56 πμ | Feng Wang, Alberto Monje, Wei Huang, Zhiyong Zhang, Guomin Wang, Yiqun Wu
Abstract
Background
Maxillary overdentures have been utilized to restore oral function in scenarios where limited bone structure represents a drawback for financial issues and for cases where oral hygiene is uncertain.
Purpose
The aim of this study was to evaluate the intermediate-term clinical outcome of four locator attachment retaining maxillary overdentures and to test their reliability.
Materials and Methods
A retrospective study was conducted from January 2007 to October 2013. After the placement of four maxillary dental implants and a healing period of approximately 3 months, all the implants were restored with locator-retained overdentures with partial palatal coverage. Subjects and implant characteristics, implant position (anterior vs posterior maxilla), bone quality, and opposing dentition were recorded. Peri-implant clinical parameters and marginal bone loss (MBL) were evaluated after delivery of the final prosthesis and annually thereafter. The performance of locator components and the prosthetic restoration were also recorded at follow-up.
Results
A total of 104 implants were placed in 26 subjects (11 women, 15 men; mean age, 64 years; age range, 55–76 years). One implant failed before loading. One subject dropped out of the study during a mean follow-up period of 46 months (range: 7–73 months), achieving an overall survival rate of 95.2%. Clinical parameters revealed healthy tissues around most of the implants, with low scores of plaque and bleeding indices. At the last follow-up evaluation, the mean MBL was 1.7 ± 1.1 mm (0.4–2.6 mm). Regression model analysis indicated that MBL for implants in the posterior maxilla was significantly higher than that for implants in the anterior maxilla (p = .0487). Overall, 26 technical and prosthetic complications were reported.
Conclusion
Within the limitations of this study, maxillary four implant-retained overdentures via Locator attachment seem to be a predictable alternative for oral rehabilitation.
Long-term Survival of Straumann Dental Implants with TPS Surfaces: A Retrospective Study with a Follow-up of 12 to 23 Years
Δευτέρα, 23 Μαρτίου 2015, 8:04:18 πμ | Stephan T. Becker, Benedicta E. Beck-Broichsitter, Christian M. Rossmann, Eleonore Behrens, Arne Jochens, Jörg Wiltfang
Abstract
Purpose
The aim of this study was to evaluate the long-term dental implant survival rates of Straumann dental implants in a university hospital environment over 12 to 23 years.
Materials and Methods
A total of 388 Straumann dental implants with titanium-sprayed surfaces (TPS) were inserted in 92 patients between 1988 and 1999 in the Department of Oral and Maxillofacial Surgery of the University Hospital Schleswig-Holstein in Kiel, and they were reevaluated with standardized clinical and radiological exams. Kaplan–Meier analyses were performed for individual factors. Cox proportional hazard regression analysis was used to detect the factors influencing long-term implant failure.
Results
The long-term implant survival rate was 88.03% after an observation time of 12.2 to 23.5 years. Cox regression revealed statistically significant influences of the International Team for Implantology (ITI) implantation type (p = .00354) and tobacco smoking (p = .01264) on implant failure. A proportion 82.8% of the patients with implant losses had a medical history of periodontitis. Peri-implantitis was diagnosed in 9.7% of the remaining implants in the long-term survey.
Conclusions
This study emphasized the long-term rehabilitation capabilities of Straumann dental implants in complex cases. The survival rates after several years constitute important information for patients, as well as for clinicians, in deciding about different concepts of tooth replacement. Patient-related and technical factors – determined before implant placement – could help to predict the risk of implant loss.
Deproteinized Bovine Bone Mineral or Autologous Bone at Dehiscence Type Defects at Implants Installed Immediately into Extraction Sockets: An Experimental Study in Dogs
Παρασκευή, 20 Μαρτίου 2015, 2:26:51 πμ | Flavia Priscila Pereira, Enzo De Santis, Eduardo Hochuli-Vieira, Eduardo F. de Souza Faco, Fabio Pantani, Luiz A. Salata, Daniele Botticelli
Abstract
Purpose
The aim of this study was to evaluate bone regeneration at surgically created dehiscence buccal defects at implants placed immediately into extraction sockets (IPIES) of small dimensions filled with autogenous bone or deproteinized bovine bone mineral (DBBM) associated with a collagen membrane.
Materials and Methods
Eight Labrador dogs were used and implants were placed immediately into the extraction sockets of the second premolar. The buccal wall was subsequently removed to create a standardized defect, 4 mm wide coronally, 2 mm wide apically, and 6 mm high. Autogenous bone particles (AB) or DBBM granules were used to fill the defects. All surgical sites were subsequently covered by a resorbable collagen membrane and a non-submerged healing was allowed. After 4 months, the animals were euthanized and bone blocks harvested and processed for histomorphometric analysis.
Results
The bony crest at the buccal aspect (C) was located 2.3 ± 0.8 mm and 1.7 ± 0.7 mm apically to the implant shoulder (IS) at the AB and DBBM sites, respectively. The coronal levels of osseointegration at the buccal aspect (B) were located 2.7 ± 0.7 mm and 2.2 ± 1.0 mm apically to IS at the AB and DBBM sites, respectively. At the AB sites, the peri-implant mucosa was located 4.3 ± 0.9 mm, 4.7 ± 0.9 mm, and 2.0 ± 1.6 mm coronally to C, B, and IS, respectively. The corresponding values at the DBBM sites were 4.3 ± 0.6 mm, 4.8 ± 0.6 mm, and 2.5 ± 0.8 mm, respectively. No statistically significant differences were found.
Conclusions
The treatment of surgically created buccal defects at IPIES sites using Bio-Oss® (Geistlich Biomaterials, Wolhusen, LU, Switzerland) or autogenous bone, concomitantly with a collagen membrane, engenders bone regeneration to a similar extent after 4 months of healing.
A Retrospective Clinical Study with Regard to Survival and Success Rates of Zirconia Implants up to and after 7 Years of Loading
Παρασκευή, 20 Μαρτίου 2015, 2:22:51 πμ | Stefan Roehling, Henriette Woelfler, Stefan Hicklin, Heinz Kniha, Michael Gahlert
Abstract
Purpose
The study aims to retrospectively investigate the clinical performance of first-generation zirconia implants with a sandblasted surface up to and after 7 years of loading.
Materials and Methods
Clinical records of patients treated with zirconia implants between 2004 and 2009 were screened. Consequently, adequate patients were invited to a clinical and radiographic investigation to classify each implant according to strict success criteria.
Results
Seventy-one patients receiving 161 implants were available for the evaluation. Overall, 36 implants (22.4%) were lost due to early (n = 14) and late failures (n = 4) or fractures (n = 18). All surviving 125 implants fulfilled the success criteria. None of the investigated implants had a history of peri-implant infections. Mean values with regard to gingival index, plaque index, modified sulcus bleeding index, and probing depth were 0.03, 0.23, 0.59, and 2.80 mm, respectively. The radiographically evaluated mean crestal bone loss was 0.97 ± 0.07 mm. Diameter-reduced implants (3.25 mm) showed lower survival (58.5%) compared with implants with a diameter of 4.0 mm (88.9%) and 5.0 mm (78.6%). The overall longitudinal survival rate was 77.3%.
Conclusions
First-generation zirconia implants showed low overall survival and success rates. The evaluated clinical and radiographic parameters were consistent with healthy peri-implant tissues. Additionally, nonfractured failures were not associated with peri-implant infections.
Osteotome Sinus Floor Elevation without Grafting: A 10-Year Prospective Study
Πέμπτη, 19 Μαρτίου 2015, 5:22:39 πμ | Rabah Nedir, Nathalie Nurdin, Lydia Vazquez, Semaan Abi Najm, Mark Bischof
Abstract
Background
Little is known about the long-term outcome of implants placed in the atrophic maxilla using osteotome sinus floor elevation (OSFE) without grafting.
Purpose
The study aims to evaluate the long-term efficiency of the procedure and stability of the peri-implant bone formed following implant placement without grafting into resorbed posterior maxilla.
Materials and Methods
Twenty-five implants (≤10 mm in length) were placed in 17 patients using OSFE without grafting. The mean residual bone height was 5.4 ± 2.3 mm. Bone levels were evaluated at 1, 3, 5, and 10 years using periapical radiographs.
Results
Fifteen patients (23 implants) participated in the 10-year examination. All implants fulfilled the survival criteria. Following surgery, the implant sites gained endo-sinus bone (mean: 3.0 ± 1.4 mm). The mean crestal bone loss (CBL) was limited to 1.0 ± 0.9 mm. The difference in mean endo-sinus bone gain and CBL was statistically significant between 1 and 10 years, but not between 3 and 5, 3 and 10, and 5 and 10 years.
Conclusions
At 10 years, the implant survival rate was 100%. Endo-sinus bone was mainly gained during the first year. This study demonstrates the long-term predictability of OSFE without grafting and simultaneous implant placement.
Esthetic Evaluation of Implant Crowns and Peri-Implant Soft Tissue in the Anterior Maxilla: Comparison and Reproducibility of Three Different Indices
Πέμπτη, 26 Φεβρουαρίου 2015, 12:05:08 μμ | Sandro Tettamanti, Christopher Millen, Jelena Gavric, Daniel Buser, Urs C Belser, Urs Brägger, Julia-Gabriela Wittneben
Abstract
Background
A successful implant reconstruction with optimal esthetics consists of a visually pleasing prosthesis and complete and healthy surrounding soft tissue. In the current literature, numerous indices used to qualitatively assess esthetics have been described. However, studies comparing the indices and their reproducibility are scarce.
Purpose
The aim of this study was to compare three different esthetic indices for the evaluation of single implant-supported crowns.
Materials and Methods
A total of 10 prosthodontists (P), 10 orthodontists (O), 10 general dentists (G), and 10 lay people (L) independently performed the same assessment using 30 photographs and corresponding casts with three different esthetic indices (Peri-Implant and Crown Index [PICI], Implant Crown Aesthetic Index [ICAI], "Pink Esthetic Score/White Esthetic Score [PES/WES]) and repeated the evaluations 4 weeks later.
Results
The PES/WES and the PICI showed significantly higher esthetic scores (pink, white, total) and clinical acceptance compared with the ICAI in all four groups and in both assessments. The highest intraobserver agreement was achieved using the PES/WES and the least with the ICAI. The mean Kappa per group ranged from 0.18 (group L with ICAI) to 0.63 (group G with PICI).
Conclusion
In comparison with the ICAI, the PES/WES and PICI were more reproducible. Therefore, PES/WES and PICI seem to be more suitable as esthetic indices for single implant crowns.
Long Term Follow-Up of Dental Implants Placed in Autologous Onlay Bone Graft
Τρίτη, 23 Δεκεμβρίου 2014, 4:28:40 μμ | Devorah Schwartz-Arad, Ronen Ofec, Galit Eliyahu, Angela Ruban, Nir Sterer
Abstract
Purpose
The aim of this study was to evaluate the efficacy of autologous intraoral onlay bone grafting (OBG) in correlation with long-term survival rates of dental implants placed in the augmented bone.
Materials and Methods
A retrospective study was conducted on 214 patients who received a total of 633 dental implants placed in 224 autologous intraoral block OBG augmentations, combined with Bio-Oss – mixed with platelet-rich plasma (PRP) and covered by platelet-poor plasma (PPP) – as scaffold, with a follow-up time up to 137 months (mean 39.9 ± 30.9 months).
Results
A total of 216 OBG cases were successful (96.4%), and most of the augmentations were uneventful (88.4%). Bone graft exposure was moderately associated with bone graft failure (χ2 = 3.76, p = .052). The healing period after implant placement was 4–6 months (mean 5.6 ± 2.56). The majority of the 591 implants survived (93.4%). The cumulative survival rate of the implants was 83%.
Conclusions
We suggest that augmentation of severely atrophied jaw bone through the placement of horizontal and/or vertical intraoral OBGs in combination with Bio-Oss saturated with PRP and covered by PPP should be considered a reliable, safe, and very effective surgical technique for obtaining high bone graft survival rate and high long-term implant survival rate.
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