Objective To evaluate the effects of different surface treatment on the fracture resistance of teeth restored with fiber posts and core system. Methods 24 fiber posts were divided into three groups according to different surface treatment techniques, including sandblasting, etching with hydrogen peroxide, and no treatment performed（the control group）. All fiber posts were luted with a composite resin luting agent in the canal roots. The teeth were restored with composite resin cores and metal crowns. After cementation, the teeth were subjected to simulated aging conditions consisting of mechanical loading cycles and thermal cycles. All teeth were loaded in a mechanical testing machine, and the fracture load and fracture mode of each teeth were recorded. Results The fracture resistances of sandblasting and hydrogen peroxide groups were higher than the control group（P0.05）. Fracture modes of all fiber post groups were nearer to the coronal third of the root. Conclusion Sandblasting and etching with hydrogen peroxide can improve the fracture resistance of teeth.
