Resistência de união de compósitos do tipo bulk fill em cavidades classe ii – influência do tipo de preparo e do armazenamento.

Abstract

Introduction: Bulk Fill composites appeared in the market and suggest the insertion of increments of 4 - 5 mm and a better marginal adaptation. Therefore it´s necessary to evaluate the behavior of these composites in conditions that simulate clinical practice. Aim: To compare the bond strength to dentin of the proximal boxes in class II cavities restored with composite of type Bulk Fill, facing the aging process in water/ethanol 75%. Material and method: Human molars were prepared in the form of class II, and divided according to the size of the Bucco-lingual opening. Then they were restored and subdivided according to composite used: Filtek Bulk Fill, Tetric Ceram N Bulk Fill and Z100 (control). After the storage in water/alcohol 75% during 30 days, the proximal boxes of samples were immediately cut into sticks to the microtensile test. The fractures were analysed in an 3 optical microscope. The data were analyzed by analysis of variance (ANOVA), Bonferroni test and t test. The analyses of the fractures occurred by means of descriptive statistics. Results: There was no statistical difference (p> 0.05) in the type of preparation and storage performance among those composite types. There was a decrease in bond strength after storage (p <0.05) in the Z100 composite and Filtek Bulk Fill composite groups. Conclusion: Bulk Fill Composite presented a performance comparable to conventional composite in terms of type of preparation and response to aging.