Effect of different monomer-based composites and acid etching pre-treatment of enamel on the microleakage using self-etch adhesives systems.

Objective: To evaluate quantitatively the marginal microleakage of restorations carried out with self-etching adhesives with or without prior phosphoric enamel acid etching of silorane or methacrylate resin-based composite restorations subjected to thermal cycling.
Materials and Methods: Forty cavities were prepared at the proximal surface of bovine incisors and randomly divided according to the etching of the enamel and restorative system used. The groups were restored with methacrylate [Adper SE Plus adhesive (3M ESPE) + Filtek Z250 (3M ESPE)] or silorane [Filtek LS adhesive (3M ESPE) + Filtek LS composite (3M ESPE)] restorative systems, light-cured using a LED unit (Bluephase 16i, Vivadent). After restorative procedure and thermocycling (1000 cycles), the specimens were immersed in methylene blue for 2 h. The specimens were triturated and the powder was used for analysis in an absorbance spectrophotometer. Data were statistically analyzed by 2-way ANOVA (alpha = 0.05).
Results: No statistical difference between the restorative materials tested with or without previous acid etching of enamel in Class II marginal microleakage was observed (p > 0.05).
Conclusions: The use of acid etching prior to self-etching adhesives did not interfere on the microleakage of methacrylate- or silorane-based restorations.