Fracture resistance of teeth restored with indirect-composite and ceramic inlay systems

Fracture resistance of dentin-bonded inlays may be influenced by the restorative material used. The purpose of this study was to evaluate, in vitro, the fracture resistance of teeth restored with four tooth-colored materials: feldspathic ceramic, Duceram LFC, and three laboratory resins, Solidex, Artglass, and Targis. Sixty mandibular molar teeth were placed in resin cylinders, reproducing the periodontal ligaments. Mesial-occlusal-distal (MOD) inlay preparations were made in a standard cavity preparation appliance. Subsequently, the teeth were molded, and the restorations were prepared following the manufacturer's instructions. The inlays were cemented with resin composite cement, Rely X, and stored at 37°C and 100% humidity for 24 hours. The samples were then submitted to an axial compression load at a speed of 0.5 mm/minute. Statistical analysis by one-way ANOVA and Tukey's multiple comparison test revealed that the teeth restored with Duceram LFC (205.44 ± 39.51 kgf) showed statistically inferior fracture resistance than the three other groups restored with indirect resin composites (Solidex [293.16 ± 45.86 kgf], Artglass [299.87 ± 41.08 kgf], and Targis [304.23 ± 52.52 kgf]).