IADR Abstract Archives
Effect of Hydrogen-Peroxide on Bond Strength of Universal-Adhesive to Eroded-Enamel
Objectives: To assess the effect of 36% hydrogen peroxide on microtensile bond strength of a universal bonding agent to eroded enamel.
Methods: 6 intact third molars were sectioned with a precision low-speed diamond saw to obtain 2 proximal rectangular enamel specimens of 8.0x4.0mm from the middle third of each tooth. All specimens were immersed in 0.1M hydrochloric acid for 2min and randomly assigned into 4 groups (n=3): no hydrogen peroxide application+7 days delay for restorative procedure (NHP:control); hydrogen peroxide+immediate restorative procedure (HPI); hydrogen peroxide+7 days delay for restorative procedure (HP7); and hydrogen peroxide+15 days delay for restorative procedure (HP15). HPI, HP7 and HP15 groups were bleached with 3 applications of 36% hydrogen peroxide gel (Nupro White Gold, Dentsply) for 15min each, following the manufacturer instructions. All specimens were restored with Prime & Bond Elect Universal (Dentsply) and Esthet-X HD composite (A2 shade, Dentsply). Specimens were sectioned to obtain sticks with a cross-section of 0.8±0.2mm2. All sticks were tested 24h after the restorative procedure at a crosshead speed of 1mm/min. The data were submitted to Kruskal-Wallis analysis followed by multiple comparisons (α=.05).
Results: The highest bond strength was obtained with the NHP group, with no significant statically difference from HP15 group (P>.05). Hydrogen peroxide reduced the bond strength to eroded enamel, with no significant statically difference among HPI, HP7 and HP15 groups (P>.05).
Conclusions: The application of 36% hydrogen peroxide reduced the bond strength of the universal bonding agent to eroded enamel.
Methods: 6 intact third molars were sectioned with a precision low-speed diamond saw to obtain 2 proximal rectangular enamel specimens of 8.0x4.0mm from the middle third of each tooth. All specimens were immersed in 0.1M hydrochloric acid for 2min and randomly assigned into 4 groups (n=3): no hydrogen peroxide application+7 days delay for restorative procedure (NHP:control); hydrogen peroxide+immediate restorative procedure (HPI); hydrogen peroxide+7 days delay for restorative procedure (HP7); and hydrogen peroxide+15 days delay for restorative procedure (HP15). HPI, HP7 and HP15 groups were bleached with 3 applications of 36% hydrogen peroxide gel (Nupro White Gold, Dentsply) for 15min each, following the manufacturer instructions. All specimens were restored with Prime & Bond Elect Universal (Dentsply) and Esthet-X HD composite (A2 shade, Dentsply). Specimens were sectioned to obtain sticks with a cross-section of 0.8±0.2mm2. All sticks were tested 24h after the restorative procedure at a crosshead speed of 1mm/min. The data were submitted to Kruskal-Wallis analysis followed by multiple comparisons (α=.05).
Results: The highest bond strength was obtained with the NHP group, with no significant statically difference from HP15 group (P>.05). Hydrogen peroxide reduced the bond strength to eroded enamel, with no significant statically difference among HPI, HP7 and HP15 groups (P>.05).
Conclusions: The application of 36% hydrogen peroxide reduced the bond strength of the universal bonding agent to eroded enamel.