Objective To investigate the clinical effect of modified adhesive retention implant denture in patients with posterior dentition defect. Methods From June 2020 to December 2021, 80 patients with posterior dentition defect admitted to Youde Dental Clinic were selected and divided into observation group (40 patients) and control group (40 patients) by random number table method. The control group was given conventional adhesive retention repair, and the observation group was given modified adhesive retention implant denture repair. The repair effect, chewing function, periodontal related indicat ors [plaque index (PLI), gingival sulcus bleeding index (SBI)] and complications were compared between the two groups. Results The height and width of mesial and distal alveolar bone in the observation group were higher than those in the control group, and the bone resorption was lower than that in the control group (P <0.05). The bite force of the two groups after operation was greater than that before operation, and that of the observation group was greater than that of the control group (P <0.05). PLI and SBI in the two groups after operation were lower than those before operation, and those in the observation group were lower than those in the control group (P <0.05). The incidence of complications in the observation group was 5.00%, which was lower than 22.50% in the control group (P <0.05). Conclusion For patients with posterior dentition defect, modified adhesive retention implant denture repair can improve the repair effect, promote the recovery of occlusal function, improve bleeding, reduce plaque formation, and reduce the incidence of complicati ons.