Influência do tipo de preparo na resistência de união de compósitos bulk fill flow - análise in vitro

Abstract

Introduction: Bulk Fill composites have gained popularity by allowing the reduction of the number of increments inserted into the cavity. Since they can be photoactivated in thicknesses of four to five millimeters, they contribute to faster clinical procedures, unlike the two millimeters required for conventional composites. Objective: To analyze the bond strength to dentin of restorations made with Bulk Fill Flow type composites in different class II preparations. Material and method: 30 third human molars were used, which were divided into six groups according to the restorative material used and the type of preparation. The adhesive system used was the same for all groups. Thereafter, the restored teeth were cut to yield toothpicks which were attached to the grips of the microtensile device. Five toothpicks were used for each tooth, totaling 25 toothpicks per group. Microtensile bond strength data were expressed in megapascal (MPa). The fractures were analyzed under an optical microscope. Data were analyzed using ANOVA, Bonferroni and t-tests (p <0.05). Results: When comparing the composites with each other, in each type of preparation, there was no statistically significant difference (p> 0.05). Compared the conservative and extensional preparation in each type of composite, there was a statistically significant difference (p <0.05) of the Bulk Fill composites. Conclusion: Bulk Fill and conventional composites had a similar performance in each type of preparation and the extensive preparation obtained lower average bond strength in the groups of Bulk Fill composites.