Effect of hyperbaric oxygen profiles on the bond strength of repaired composite resin

OBJECTIVE: This study was performed to evaluate the bond strength of repaired three types of composite resins under various hyperbaric oxygen (HBO) profiles with various session numbers. MATERIALS AND METHODS: Sixty specimens of three types of composite resin (nanofilled composite, nanohybrid composite and microfilled composite) each type of composite was divided into four group according to various profiles of HBO treatment (control, 2bar, 3 bar and 5 bar). Then, the specimens were repaired; thermocycled, the tensile bond strength were measured. Then the data were analyzed by One-way ANOVA followed by Tukey's post hoc test (α = 0.05). RESULTS: The highest bond strength was obtained for the repaired nanofilled composite resin specimens while; the lowest bond strength was obtained for the repaired microfilled composite resin specimens. The highest tensile bond strength was recorded for the specimens who treated with the highest pressure of HBO. CONCLUSION: The bond strength of repaired nanofilled composite resins is better than the other types of composite resin. The highest pressure of HBO, the highest bond strength of repaired composite resins.