Shear bond strength of two adhesive materials to eroded enamel

Aim: To evaluate the bond strength of one etch-and-rinse adhesive system and one resin-modified glass ionomer cement to sound and eroded enamel. Materials and methods: Forty-eight bovine incisors were embedded in acrylic resin and ground to obtain flat buccal enamel surfaces. Half of the specimens were submitted to erosion challenge with pH-cycling model (3x/cola drink for 7 days) to induce eroded enamel. After that, all specimens were randomly assigned according to adhesive material: etch-andrinse adhesive system (Adper Single Bond 2 – 3M ESPE, USA) or resin-modified glass ionomer cement (Vitro Fil LC – DFL, Brazil). The shear bond testing was performed after 24 hours water storage (0.5 mm/min). Shear bond strength means were analyzed by two-way ANOVA and Tukey post hoc tests (p < 0.05). Results: Adper Single Bond 2 showed the highest bond strength value to eroded enamel (p < 0.05), whereas no difference was observed in sound enamel compared with Vitro Fil LC (p > 0.05). Conclusion: Bond strength of etch-and-rinse adhesive system increases in eroded enamel, while no difference is verified to resin-modified glass ionomer cement. Clinical significance: Adhesive materials may be used in eroded enamel without jeopardizing the bonding quality; however it is preferable to use etch-and-rinse adhesive system