Diferentes métodos de acabamento e polimento de restaurações de resina composta em cavidades Classe V e seus efeitos sobre a rugosidade superficial, eliminação de excessos e desgastes iatrogênicos

Abstract

The objective of this study was to evaluate the effects of three finishing and polishing methods on the surface roughness of Class V cavities on natural teeth restored with composite resin, as well as the efficiency in removing composite excesses and the tendency to produce iatrogenic tooth abrasion. Standardized Class V cavities were prepared at the amelodentinal junction on the buccal surface of sixty human premolar teeth. The cavities were filled with a nanoparticulate composite resin (Z350 Filtek Supreme XT, 3M ESPE, Sumare, SP, Brazil), and the teeth were randomly assigned to three groups with different finishing and polishing techniques: G1 (diamond burs and abrasive rubber points), G2 (diamond burs and surface sealant), and G3 (abrasive discs and abrasive spiral discs). The teeth were positioned on a dental dummy head to simulate clinical conditions. A profilometer analyzed the average surface roughness (Ra) of the restorations, 3-D images were obtained using the Talymap software, and microscopy images were taken with a micro stereoscope. Ra data were statistically analyzed using the Kruskal-Wallis test (p<0.05). Ra values cited in ascending order were: G3 (0.64 μm), G2 (0.69 μm), and G1 (0.90 μm). The G3 group showed significantly lower Ra values than the G1 group (p=0.036). The qualitative analysis showed iatrogenic abrasion of the root cementum on the gingival margins of the restorations in group G3 and an excess of composite and sealant on the gingival margin in groups G1 and G2. The G2 group also presented images with undulations on its surface, presenting a more irregular microtopography than the others. The finishing and polishing technique with abrasive discs and abrasive spiral discs provided a surface with lower surface roughness in composite resin restorations of Class V cavities on natural teeth than the technique of diamond burs and abrasive rubber points. However, none of the methods provided a restoration with the Ra value recommended according to the literature or without an excess of composite resin or iatrogenic tooth abrasion.