Bioactive dental materials—Do they exist and what does bioactivity mean?

Publication date: Available online 20 March 2018
Source:Dental Materials
Author(s): Pekka K. Vallittu, Aldo R. Boccaccini, Leena Hupa, David C. Watts




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Correction to: Subcutaneous lipomas: A minimally invasive method for resection of subcutaneous lipomas preserving retaining ligaments

Abstract

The article Subcutaneous lipomas: A minimally invasivemethod for resection of subcutaneous lipomas preserving retaining ligaments, written by Akio Sakamoto, Takeshi Okamoto, Shuichi Matsuda, was originally published electronically on the publisher's internet portal (currently SpringerLink).

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Effect of simulated acid rain on fluorine mobility and the bacterial community of phosphogypsum

Abstract

Contamination of soil and water with fluorine (F) leached from phosphogypsum (PG) stacks is a global environmental issue. Millions of tons of PG is produced each year as a by-product of fertilizer manufacture, and in China, weathering is exacerbated by acid rain. In this work, column leaching experiments using simulated acid rain were run to evaluate the mobility of F and the impact of weathering on native bacterial community composition in PG. After a simulated summer rainfall, 2.42–3.05 wt% of the total F content of PG was leached and the F concentration in leachate was above the quality standard for surface water and groundwater in China. Acid rain had no significant effect on the movement of F in PG. A higher concentration of F was observed at the bottom than the top section of PG columns suggesting mobility and reprecipitation of F. Throughout the simulation, the PG was environmentally safe according the TCLP testing. The dominant bacteria in PG were from the Enterococcus and Bacillus genus. Bacterial community composition in PG leached by simulated acid rain (pH 3.03) was more abundant than at pH 6.88. Information on F mobility and bacterial community in PG under conditions of simulated rain is relevant to management of environmental risk in stockpiled PG waste.

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Biochemical and morphological biomarkers of the liver damage in the Neotropical fish, Piaractus mesopotamicus , injected with crude extract of cyanobacterium Radiocystis fernandoi

Abstract

Cyanobacterial proliferation in river and lakes is the result of eutrophication. The cyanobacterium Radiocystis fernandoi strain R28 produces mostly two MC variants MC-RR and MC-YR and small amounts of other oligopeptides, but does not produce MC-LR. The present study investigated the hepatotoxic potential of the crude extract of the R. fernandoi strain R28 on the Neotropical fish, Piaractus mesopotamicus, at 3, 6, and 24 h after intraperitoneal injection (100 μg MC-LR equivalent per kg⁻¹ body mass) using biochemical and morphological biomarkers of liver damage. Although the protein phosphatases PP1 and PP2A were not inhibited during the 24-h treatment, liver parenchyma and hepatocyte structure were disrupted. Alkaline phosphatase increased at 3 h post-injection and decreased after 24 h; alanine aminotransferase and aspartate aminotransferase increased in a time-dependent manner up to 24 h indicating impaired liver function. Progressive histopathological changes were consistent with biochemical results demonstrating alterations in liver structure and function. In conclusion, the crude extract of R. fernandoi strain R28 has high hepatotoxic potential and can severely compromise fish health.

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Effect of photobiomodulation on connective tissue remodeling and regeneration of skeletal muscle in elderly rats

Abstract

The purpose of this study was to evaluate the effects of low-level laser therapy (LLLT) on morphological aspects, IL-6 and IL-1β expressions, as well as the distribution and organization of collagen in the tibialis anterior (TA) muscle of elderly rats submitted to cryoinjury. Histological photomicrographs were taken of TA muscles stained with HE and picrosirius red. Immunohistochemistry was used for the evaluation of IL-6 and IL-1β. Male Wistar rats, aged 20 months, were distributed into three groups: (1) control animals not injured or treated with LLLT (n = 5), (2) cryoinjury without LLLT treatment (n = 15), and (3) cryoinjury treated with infrared LLLT (n = 15). LLLT was applied to the TA 2 h after of the injury induction and consisted of daily applications until the sacrifice (1, 3, and 7 days). The following parameters were used: λ = 780 nm, power density 1 W/cm², output power 40 mW, 10 s per point, 8 points, and 3.2 J of total energy. In the histomorphological analysis, the treated group exhibited a significant decrease in inflammatory infiltrate (p < 0.001) as well as an increase immature fibers and new blood vessels at 7 days compared to the untreated group (p < 0.05). Furthermore, treatment induced a better collagen distribution and organization at 7 days in comparison to the untreated group (p < 0.05). In conclusion, LLLT demonstrated a modulatory effect on the muscle repair process in elderly animals with regard to the collagen remodeling and morphological aspects of muscle tissue.

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Photobiomodulation effect on children’s scars

Abstract

The management of burn scars has become one of the major clinical challenges in the developing countries which involve enormous treatment cost; this needs new methods for better cost benefit relationship. The objective of the study is to analyze the effectiveness of low-level laser therapy on post-burn scar tissue in children. A randomized controlled study included 15 children, ranging from 2 to 10 years of age, presenting with burn scars. They received diode laser and topical treatment. Each scar was divided into two halves. One half was treated with laser therapy and topical treatment (study area), and the other half was treated with topical treatment only (control area). The children were evaluated before and after 3 months of the study by Vancouver Scar Scale (VSS), ultrasonography (U/S), and laser Doppler perfusion imaging. Significant improvement was reported in the studied area compared to the control area for patients with P values (P = 0.005) and (P = 0.0001) for VSS and U/S scores, respectively. No difference was detected for blood perfusion to the scar between both areas (P = 0.18). In addition, no adverse effect was reported. Photobiomodulation is an efficient and safe therapeutic modality for post-burn hypertrophic scars in children and should be considered a part of combination therapy for better results.

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Comparison of the effect of root surface modification with citric acid, EDTA, and aPDT on adhesion and proliferation of human gingival fibroblasts and osteoblasts: an in vitro study

Abstract

Root demineralization is used in Periodontics as an adjuvant for mechanical treatment. The aim of this study was to evaluate the effects of root surface modification with mechanic, chemical, and photodynamic treatments on adhesion and proliferation of human gingival fibroblasts and osteoblasts. Root fragments were treated by scaling and root planing (C—control group), EDTA (pH 7), citric acid plus tetracycline (CA—pH 1), and antimicrobial photodynamic therapy (aPDT) with toluidine blue O and red laser (pH 4). Cells were seeded (104 cells/well, 6th passage) on root fragments of each experimental group and cultured for 24, 48, and 72 h. Cells were counted in scanning electron microscopy images by a calibrated examiner. For fibroblasts, the highest number of cells were present at 72-h period (p < 0.05). EDTA group showed a very low number of cells in relation to CA group (p < 0.05). CA and aPDT group presented higher number of cells in all periods, but without differences between other treatment groups (p > 0.05). For osteoblasts, there was a significant increase in cell numbers for aPDT group at 72 h (p < 0.05). In conclusion, aPDT treatment provided a positive stimulus to osteoblast growth, while for fibroblasts, aPDT and CA had a tendency for higher cell growth.

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