Comparative evaluation of different methods of saliva decontamination on microshear bond strength of composite to composite: An in vitro study.

Background: During the incremental technique of composite restorations, it is possible to be exposed to contamination of the oral environment. This study aimed to compare the effect of saliva contamination and different methods of saliva decontamination on microshear bond strength within composite surfaces.

Materials and methods: This in vitro study created 24 rectangular XT composite blocks using a silicone mold (24 mm × 10 mm × 10 mm). The blocks were divided into eight groups as follows: Group 1: Control group (without contamination); Group 2: Contaminated with saliva; Group 3: saliva + dried; Group 4: saliva + rinsed + dried; Group 5: saliva + rinsed + dried + Clearfil Self Etch Bond; Group 6: saliva + 96% ethanol alcohol; Group 7: saliva + chlorhexidine + rinsed + dried; and Group 8: saliva + rinseddried + All-Bond Universal bond. Fifteen tubes (0.7 mm × 1 mm) were attached to the prepared surfaces in each group, with five tubes allocated to each block. They were filled with composite and light-cured and stored in distilled water for 24 h. They were tested under a microshear test. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey's honest significant difference (HSD) test (P < 0.05).

Results: One-way ANOVA test demonstrated significant differences among the groups concerning the mean bond strength (P < 0.001). Tukey's HSD test indicated that the bond strengths in groups 6 and 8 were similar to the control group, showing no significant difference. The lowest bond strength was observed in group 2, which measured 6 MPa.

Conclusion: Decontamination with rinsed + dried + All-Bond Universal bond and 96% ethanol alcohol were the most effective methods for improving the contaminated composites' microshear bond strength.