Efeito do modo de aplicação no desempenho de adesivos autocondicionantes simplificados à dentina

Abstract

The purpose of this study was to evaluate the effect of different application modes on the immediate and 6-month resin-dentin bond strength and silver nitrate uptake. Three one-step self-etch adhesive systems (One Coat 7.0 [OC], Coltène Whaledent; Clearfil S3 Bond [CS], Kuraray and FuturaBond NR [FB], Voco) were applied in a flat superficial dentin surface of thirty human molars under slight [S] or vibratory [V] application modes. Composite build-ups (Opallis, FGM) were constructed incrementally. After water storage at 37 °C for 24 h, teeth were sectioned to obtain sticks with cross-sectional area of 0.8 mm2 to be tested in tension (0.5 mm/min) either immediately [IM] or after 6 months [6M] of water storage. Two bonded sticks from each tooth at each storage time were immersed in a 50% (w/v) solution of silver nitrate (24 h), photo-developed (8 h) and analyzed under SEM. The silver nitrate uptake was measured using the ImageTool 3.0 software. The data from each adhesive were analyzed by two-way ANOVA and Tukey’s test (α = 0.05). The adhesives OC and CS showed higher resin-dentin bond strength values and lower silver nitrate deposition in the immediate time and vibratory application groups. For FB, no significant difference was observed between the two modes of application in the respective storage periods. The vibratory application mode can improve the resin-dentin bonds, reduce the silver nitrate uptake and retard the degradation of the resin-dentin bonds of Clearfil S3 Bond and One Coat 7.0 adhesives.