Effect of bonded gold inlays on fracture resistance of teeth.

The purpose of this study was to determine if bonding gold inlays to tooth structure with an adhesive resin cement would increase the fracture resistance of restored teeth. Extracted paired maxillary premolars were prepared for mesio-occlusodistal inlays, and the inlays were cast in type II gold. In one tooth of each pair, the inlay was sandblasted with aluminium oxide, tin plated, and cemented with an adhesive resin into the etched preparation. For the other (control) tooth in each pair, the inlay was sandblasted and then cemented into the preparation with zinc phosphate cement. The teeth were thermocycled and loaded until fracture. The teeth in the bonded group had a statistically significantly higher fracture resistance than did the teeth in the control group. Scanning electron microscopic examination revealed that failure in the bonded group occurred predominantly within the resin.