Microinfiltração em restaurações com resinas compostas de baixa contração de polimerização

Abstract

The aim of this in vitro study was to assess the marginal microleakage in restorations with different bulk-fill resin composite (RBC) when compared with a conventional resin-based composite (RC). Standardized cavities in the buccal aspect of bovine central incisors were made. The prepared teeth were randomly distributed into five groups according to restorative material: FTKC (RC Filtek Z350 XT/3M ESPE); FTKBC (RBC Filtek Bulk Fill /3M ESPE); ARBC (RBC Aura Bulk Fill/SDI); TNBC (RBC Tetric N Ceram Bulk Fill/Ivoclar Vivadent); and SF (RBC SonicFill/Kerr). After thermocycling the samples were immersed in aqueous solution to 1% methylene blue for 24 hours. The teeth were subsequently sectioned in the region of the restorations in the cervical incisal direction. For each sample, images of the two restored margins (I – incisal; C – cervical) were obtained using a stereomicroscope with 20x magnification. The microleakage degree was classified through an ordinal score system (0 to 4). For the statistical analysis, the Kruskal-Wallis test were as used to evaluate the microleakage of different composite resins (α= 0.05), and the Wilcoxon test were as used to compare the microleakage between the analyzed margins (α= 0.05). The results showed no significant difference in microleakage between the groups, between the different RBCs and between the different evaluated margins (C and I) of the restoration. It is concluded that, regardless of the evaluated margin of restoration, the marginal microleakage of the different RBCs is similar to that of a RC; in addition, we were found no differences in marginal microleakage among the evaluated RBCs.