Abstract: Objective To evaluate the effects of diode laser on the treatment for chronic periodontitis patients with type 2 diabetes mellitus. Methods 960 sites from 40 periodontitis patients with type 2 diabetes were randomly divided into experiment group and control group. Patients in experiment group were treated with initial therapy and diode laser therapy, meanwhile, only initial therapy was performed for the patients in control group. Sulcus Bleeding Index (SBI), probing depth (PD), clinical attachment loss (CAL) and systemic indexes (hs-CRP, HbA1c, GLU) were recorded before treatment, 3 months and 6 months after treatment. Results For both groups, 3 months and 6 months after treatment, all the indexes were significantly lower than those before treatment（P＜0.05）. 3 months after the treatment, SBI, PD and all the systemic indexes in experiment group were significantly lower than those of control group（P＜0.05）. 6 months after the treatment, SBI, PD and HbA1c were significantly lower than those of control group（P＜0.05）. And the differences of AL, HbA1c, GLU between two groups were not significant（P＞0.05）. Conclusion Diode laser is an effective adjuvant treatment for periodontitis patients with type 2 diabetes, especially for the relief of inflammation and the glucose metabolism in short term.

Key words: diode laser, type 2 diabetes mellitus, chronic periodontitis, glycosylated hemoglobin