Abstract: Objective： To compare the clinical effect of root canal repair after root canal therapy and implant re- pair after extubation, and the difference of VAS in patients with residual crown. Methods： From January 2016 to January 2018, 60 patients with residual crown were divided into observation group and control group. The observation group was treated with residual crown root canal and the control group was treated with tooth residual crown extraction. The visual analogue scale and visual analogue score(VAS) were com- pared between the two groups. Results： Three months after treatment, the clinical effects of the observa- tion group were better than those of the control group in four aspects: root stability, loosening of teeth, fixa- tion effect of prosthesis and masticatory function (P<0.05). The satisfaction rate of the patients repaired af- ter root canal therapy was 83.3%, and that of the patients with implant repair after extraction was 66.7%. The difference was statistically significant(P<0.05). VAS of the two groups showed that the pain degree was significantly reduced with the prolongation of the distance treatment time, but the pain degree of the observation group was lighter, the pain relief was faster, and the comfort degree of the patients was higher. Conclusion： The former has less pain and better effect than that after extraction, so it is worth choosing first.

Key words: tooth crown, root canal repair, extraction and implant repair, VAS