Effect of resin-based materials on fracture resistance of endodontically treated thin-walled teeth

Statement of problem Composite resins are recommended for root reinforcement, but little information exists about self-adhesive resin cements that eliminate the acid etching and bonding steps. Purpose The purpose of this study was to compare the fracture resistances of teeth restored with 2 different diameters of cast and fiber posts and to evaluate the effectiveness of increasing internal root thickness with 2 resin-based materials to reinforce thin-walled teeth. Material and methods Ninety maxillary incisors were endodontically treated and divided into 9 groups. In the first 4 groups, teeth were restored with tapered end cast (C1.3 and C1.7) and fiber (F1.3 and F1.7) posts of 1.3 and 1.7 mm diameters. In the other 5 groups, the root canals were enlarged to simulate the thin-walled teeth and restored with low viscosity composite resin with fiber posts of 1.3 and 1.7 mm diameters (LF1.3 and LF1.7), self-adhesive resin cement with fiber posts of 1.3 and 1.7 mm diameters (SF1.3 and SF1.7), and cast posts of 4 mm diameter that fit in post spaces (C4). Teeth were loaded to fracture at a 135-degree angle to their long axis. Data were analyzed with 2-way ANOVA and the Tukey HSD test (α=.05). Results Significant difference ( P P Conclusions The fracture resistance of the teeth increased as the elastic modulus of the posts increased but was not affected by small diameter variations of the posts. The resin-based materials were able to preserve and reinforce the remaining tooth structures.