Abstract: Objective: To compare the clinical effect of two kinds of bone drills in the posterior implant site. Methods: From February 2017 to March 2018, 50 patients were selected, all of them were implant patients in the posterior teeth area, and there were small bone defects in the implant area, a total of 58 implants were implanted, 29 of which were drilled with ring-shaped bone extraction, set as group A; 29 of which were drilled with self grinding bone extraction, set as group B. After 12 months, the absorption of bone graft materials was measured and the 1-year survival rate was compared between the two groups. Data were analyzed by SPSS 25.0. Results: One year after repair, the average bone resorption was 0.56mm in group A and 0.58mm in group B, and the survival rate was 100% 12 months after repair. Conclusion: Two kinds of bone drills can be used as bone graft materials at the implant site, and can achieve satisfactory clinical results. But the scope of application is different.

Key words: posterior area, implant, bone drill, simultaneous bone graft