Abstract: Objective To compare the effects of different repair methods on different types of wedge-shaped defects with exposed pulp. 
Methods Eighty patients receiving repair for different types of wedge-shaped defect with exposed pulp in mandibular premolars after root canal treatment in Department of Prosthodontics, School of Stomatology, Hebei Medical University, were selected. They were divided into group A1 (wedge-shaped defect within 1/3 in width, and treated with resin filling + crown restoration, n=20), group A2 (edge-shaped defect within 1/3 in width: fiber post-and-core + resin filling + crown restoration, n=20), group B1 (wedge-shaped defect more than 1/3 and less than the axial angle in width: resin filling + crown restoration, n=20) and group B2 (wedge-shaped defect more than 1/3 and less than the axial angle in width: fiber post-and-core + resin filling + crown restoration, n=20) based on the width of wedge-shaped defects and repair method. The success rate of repair treatment and the repair effect were compared in the four groups. 
Results At 2-year reexamination after repair, there was no significant difference in the success rate of repair treatment and repair effect between group A1 and group A2 (P＞0.05). The success rate of repair treatment and repair effect in group B2 was higher or better than those in group B1, and the difference was statistically significant (P＜0.05). 
Conclusion When the wedge defect is less than 1/3 in width, direct resin filling can achieve good repair effect, whereas when the wedge defect is more than 1/3 but does not exceed the axial angle in width, supplementation of fiber post can improve the success rate.

Key words: bicuspid, dental restoration, permanent, wedge-shaped defect, fiber post