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All repair systems tested increased the bond strength values between zirconia and composite resin that used surface grinding with a diamond bur.

Debonding at the composite-adhesive interface is a major problem for indirect composite restorations. The aim of this study was to evaluate the bond strength (BS) of an indirect composite resin after various surface treatments (air-abrasion with Al2O3, phosphoric acid-etchig and different applications of NdYAG laser irradiations). Fifty composite disks were subjected to secondary curing to complete polymerization and randomly divided into five experimental groups (n = 10) including Group 1, untreated (control); Group 2, phosphoric acid-etched; Group 3, air-abrasion with Al2 O3 ; Group 4, Nd:YAG laser irradiated with non-contact and Group 5, Nd:YAG laser irradiated with contact. They were then bonded to resin cement and shear BS was determined in a universal testing device at a crosshead speed of 1 mm/min. One way analysis of variance (ANOVA) and Tukey post-hoc tests were used to analyze the BS values. The highest BS value was observed in Group 4 and followed by Group 3. Tukey test showed that there was no statistical difference between Group1, 2 and 5. Furthermore, differences in BSs between Group 4 and the other groups except Group 3 were significant (p < 0.05) and also there were significant differences in BSs between Group 3 to 1 and Group 3 to 2 (p < 0.05). This study reveals that air-abrasion with Al2 O3 and Nd:YAG laser irradiation with non-contact provided a significant increase in BS between indirect composite and resin cement.

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In Shear bond strength of resin, cement was independent of the surface conditioning methods applied on tested indirect resin composite.

Objective: The aim of this in vitro study was to evaluate the effect of whitening mount rinses on superficial roughness a nanofilled resin composite. Methods: Sixty-three nanofilled composite resin specimens (8 mm x 2 mm) were prepared and randomly divided into seven groups, according to the mouthrinse solutions (n = 9): Oral-B 3D White, Crest 3D White, Colgate Optik Beyaz, Scope White, Signal White Now and Listerine Whitening Vibrant. The control group used in the study was distilled water. The initial surface roughness measurements (Ra) were measured with a profilometer and then the each sample was immersed in 2 mL of the mouthrinses for 14 days period. After immersion period, roughness readings were repeated and the data were analyzed with ANOVA and Scheffe test (p<.05). Results: The profilometric assessment showed that exposure to mouthrinse resulted in a slightly increase in roughness values in all groups. But, the differences between mouthrinses groups and the control group were not statistically significant (p > 0.05). Conclusion:We conclude that the influence of the whitening mouthrinses on the surface roughness of dental resin composite was negligible.

The aim of this study is to determine the compressive strength values of three bulk fill composite resins polymerized at two different layer thicknesses and two different light power.Material and methods: In this study, three different bulk fill composite resins (