Objective To evaluate the effect of periodontal therapy on glycaemic control in type 2 diabetic associated periodontitis patients, and explore the role of periodontal therapy in the treatment of diabetes. Methods Studies of periodontal therapy on glycaemic control in diabetic patients were searched in Cochrane Central Register of Controlled Trials（Central）, Medline, EMbase, SIGLE, GreyNet, NTIS, CBMdisc, VIP, CNKI and Wanfang data from 1991 to April 31, 2011. The studies’selection, extraction and evaluation were performed by two reviewers independently, and meta-analysis was performed with RevMan 5.1 software. A total of 7 studies involving 471 participants were included in the review. Results Periodontal treatment could lead to a significant reduction in glycosylated hemoglobin level. The difference between the groups was significant（95%CI: -0.94 to -0.22, P= 0.001）. And the periodontal probing depth in the treatment group was lower than those of the control group, the difference between the groups was also statistically significant（95%CI: -2.26 to -0.69, P=0.000 2）. Conclusion Periodontal treatment could improve glycaemic control in type 2 diabetic associated periodontitis patients.
