Resistência à Fratura de Dentes Tratados Endodonticamente e Restaurados com Diferentes Técnicas e Materiais Dentários

Abstract

Endodontically treated teeth present a greater risk of fracture compared to teeth with pulp vitality. Fractures are more concentrated in premolars due to their anatomical shape, unfavorable crown-to-root ratio and exposure to shear and compressive forces. Furthermore, endodontic access and often the instrumentation itself compromise structural integrity of the coronal portion, resulting in greater cusp deflection during function, especially in mesio-occluso-distal (MOD) cavities. In order to increase resistance to fracture, intraradicular posts and fibers for structural reinforcement (glass fiber or polyethylene fiber) can be used. Several materials and techniques are described in the literature for the restoration of teeth with MOD cavities, such as composite resins and dental ceramics recommended for direct or indirect techniques. In this study, 50 endodontically treated upper first premolars were used, with MOD preparation and restored according to the groups (n=10 described below: (GI) direct restoration with microhybrid composite resin (control); (GII) direct restoration with microhybrid composite resin and intraradicular fiberglass posts; (GIII) direct restoration with microhybrid composite resin and braided fiberglass tape (GIV) direct restoration with microhybrid composite resin and reinforcement with glass fiber post fragments and (GV) indirect restoration with feldspathic ceramics. Once the restorative procedures were completed, the teeth were stored in an oven for 24 hours and subjected to compression tests until the set fractured. The average values obtained in this study (GI 495,70N; GII 463,13N; GIII 921,47N; GIV 628,45N; GV 510,93N), considering its limitations, demonstrate that there is no material that increases fracture resistance in a statistically significant way. However, it is important to observe the averages and medians presented for groups III (Interlig) and IV (Pin Fragments) with higher numerical values in relation to fracture resistance.