Avaliação da influência de dois sistemas adesivos na cor de restaurações de resina composta

Abstract

Direct esthetic restorations are a conservative alternative for anterior teeth with changes in color or anatomical form. The color stability of resin composites is still a challenge and can be affected by the adhesive degradation. Therefore, these two in vitro studies investigated the influence of two adhesive systems (Ambar APS and Scotch Bond Universal) on the color stability of two resin composites (Filtek Z350 XT and IPS Empress Direct), immediately afterwards and over time (aging). A total of 4 groups were produced in the first study according to the adhesive system and the restorative system, divided into 7 subgroups (n=5) from the restorative combinations. Then 5 groups were formed in the second study with the same materials, divided into 15 subgroups (n=5). Evaluations were performed using a reflection spectrophotometer (SP60, EX-Rite) after immersion in deionized water for 24 hours (T0) and after aging for different periods: 1 month (T1), 6 months (T2) and 12 months (T3). Comparative analyzes were performed between the color reading on the different substrates in the times from the CIELAB and CIEDE2000 equations, and also for qualitative parameters. The mean inter and intragroup ΔEab and ΔE00 values were analyzed using ANOVA - MR and post hoc Bonferroni (α=0.05). It was observed in both studies that the three aspects evaluated (adhesive, resin composite and time) were statistically significant. It was further noted in the qualitative evaluation that Scotchbond Universal obtained clinically more acceptable results than Ambar. Moreover, that the greater change occurs in the L coordinate, meaning in the restoration’s luminosity. This information supports the argument that the chromatic instability produced by combining different resin thicknesses represented in most groups lies is in the change in opacity.