Internal adaptation of resin composites at two configurations: Influence of polymerization shrinkage and stress

Publication date: Available online 30 June 2016
Source:Dental Materials
Author(s): Seung-Hoon Han, Alireza Sadr, Junji Tagami, Sung-Ho Park
ObjectiveThis study compared internal adaptation of composites under different C-factors and examined the relationship between internal adaptation and polymerization shrinkage parameters.MethodsCylindrical cavities 3mm in diameter were prepared in 100 human third molars in two depths: 4mm high C-factor (H-CF) or 1mm low C-factor (L-CF). After adhesive application (Clearfil SE One, Kuraray Noritake), the composite was placed in two increments in three subgroups: Filtek Supreme (FS, 3M ESPE); Charisma Diamond (CD, Heraeus Kulzer); Amelogen Plus (AP, Ultradent); and as a single increment in two subgroups: Tetric EvoCeram Bulk Fill (TB, Ivoclar Vivadent) and Venus Bulk Fill (VB, Heraeus Kulzer). After thermo-mechanical load-cycles, imperfect margin percentage (%IM) was calculated using swept-source optical coherence tomography (SS-OCT) imaging. The relationships between %IM and linear shrinkage (LS) and shrinkage stress, measured under either zero-compliance (PS0) or compliance-allowed (PS) conditions were evaluated.ResultsThe %IM was significantly different between H-CF and L-CF groups. The %IM in H-CF turned out to be as groups CD, FS≤TB<AP, VB. The %IM in L-CF showed as groups CD, TB≤FS, AP<VB. There were significant correlations between shrinkage parameters and %IM, except between PS0 and %IM in L-CF.SignificanceInternal adaptation in a high C-factor cavity was inferior to that in a low C-factor cavity for both conventional and bulk-filled composites. Internal adaptation, polymerization shrinkage, and stress were different among composite materials. Polymerization stress under the compliance-allowed condition showed significant correlations with internal adaptations in high and low C-factor cavities.



http://ift.tt/2982o6m


from #Med Blogs by Alexandros G.Sfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/298wNBy
via IFTTT