Objective To investigate the restorations outcome of fibre post + composite resin + zirconia porcelain crown for patients with wedge-shaped defects（WSD）in posterior teeth after root canal therapy（RCT）．Methods A total of 300 patients（300 teeth）with posterior WSD after RCT in our hospital（from August 2019 to August 2022）were selected and divided into group A（n=150）and group B（n=150）according to random number table method．Group A received composite resin + zirconia porcelain crown + fiber post repair treatment,while group B received porcelain fused to metal（PFM）+ metal post core（MPC）repair treatment．The success rate of repair,the effect of repair,the periodontal health indicators before and after repair[gingival index（GI）,plaque index（PLI）,periodontal probing depth（PD）],and the levels of gingival creval fluid inflammatory factors[interleukin-6（IL-6）,IL-10,tumor necrosis factor-α（TNF-α）] were compared between the two groups．Results The success rate of repair in group A was 97.33%（146/150）,higher than 87.33%（131/150）of group B（P<0.05）．The edge tightness,surface texture and color matching of group A were better than those of group B（P<0.05）．After 6 months of repair,GI,PLI and PD in group A were lower than those in group B（P<0.05）．After one month of repair,the contents of TNF-α and IL-6 in gingival crevicular fluid of group A were lower than those of group B,and the contents of IL-10 were higher than those of group B（P<0.05）．Conclusions Compared with PFM+MPC in the treatment of posterior WSD patients after RCT,the application of composite resin + zirconia porcelain crown + fiber post repair is more helpful to improve the success rate and effect of repair,improve periodontal health,and cause less tissue trauma．