Objective: To evaluate the influence of various cavity designs, lining and restorative materials on fracture resistance of teeth in vitro.
Methods: Factorial design with three factors and various levels was used. 36 extracted human maxillary premalors were prepared for occlusal cavity, MO cavity and MOD cavity. Various base material and restorations were used. All teeth were thermocycled and mounted for testing and then were loaded until fracture. The results were analyzed by a three-way ANOVA. Fracture patterns were observed at the same time.
Results: There was significant difference in fracture resistance among various cavity designs and restorations. The fracture patterns were different.
Conclusions: The different classes of cavities and various restorations have significantly influence upon fracture resistance of teeth. There are interactions between cavities and restorations.