Influência da técnica restauradora e do tempo de envelhecimento na resistência ao cisalhamento por extrusão (push-out), nanoinfiltração e profundidade de polimerização em cavidades profundas

Abstract

INTRODUCTION: Restorative techniques make a fundamental role in the clinical longevity of restorations, especially in deep composite resin cavities. OBJECTIVE: The aim of this study was to evaluate the influence of the restorative technique (direct incremental, direct single fill and semi-direct) and aging time (24 hours and 6 months) on extrusion shear strength (push-out), nanoleakage (NK) and depth of polymerization (DP) in cavities deep. METHODS: A total of 120 bovine incisives (n=20) were used to separate the root and the coronary portion, with a cavity preparation of 4.8mm in diameter, 2.8mm in diameter and 4.0mm in depth. . As examples were divided into 6 groups according to the restorative technique and working time: BF 24hs, SD 24hs, CONV 24hs, BF 6 months, SD 6 months and CONV 6 months. The tests performed were depth of polymerization (DP), nanoleakage (NK) and extrusion shear strength (push-out). Data were applied using descriptive and inferential statistics using Two Way ANOVA with Tukey Post Hoc (p <0.005). RESULT: For push-out, there was a statistically significant variation between restorative variables (p <0.005), where the semidirect technique presented better results. Still in this analysis, there was no significant difference without aging time (p> 0.005) for each technique. For DP there was no statistically significant difference between restorative techniques at any time of analysis (p> 0.005). At NK, the semidirect technique did not show concentration of silver crystals at the adhesive interface, thus demonstrating better results than the conventional and single fill technique. CONCLUSION: The semidirect technique, due to its good mechanical behavior and the lower incidence of nanoleakage at the adhesive interface, can be indicated in deep posterior teeth cavities.