·Periodontal examination and questionnaire survey were conducted on patients with type 2 diabetes mellitus who visited the Department of Endocrinology, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University from November 2018 to December 2018. The periodontal indexes of index teeth were examined and scored, including probing depth, bleeding on probing, clinical attachment loss (CAL), calculus index (CI) and plaque index (PLI). According to the diagnostic criteria of periodontitis, the subjects were divided into periodontitis group and non-periodontitis group. The prevalence of periodontitis and related periodontal indexes in patients with type 2 diabetes mellitus of different ages were compared.

·In the 916 patients with type 2 diabetes mellitus, the difference of age between the periodontitis group and non-periodontitis group was statistically significant (χ²=100.1, P=0.001). Multivariate Logistic regression analysis indicated that age was a high-risk factor for type 2 diabetic periodontitis (P=0.001, OR=2.13, 95%CI 1.79?2.55). Compared with younger patients with diabetes mellitus, elderly patients with diabetes mellitus were more likely to have periodontal symptoms such as gingival bleeding (χ²=36.4, P=0.001), tooth loosening (χ²=25.9, P=0.002) and masticatory weakness (χ²=12.3, P=0.006). There were significant differences in PLI (χ²=8.3, P=0.041), CI (χ²=12.8, P=0.005) and CAL (χ²=32.5, P=0.001) among diabetic patients of different ages. There were significant differences in periodontal health care measures, such as brushing teeth (χ²=18.8, P=0.001), rinsing mouth with water (χ²=21.8, P=0.001) and frequency of tooth brushing (χ²=24.0, P=0.001).

·The age of diabetic patients is a risk factor affecting the prevalence rate and severity of periodontitis. It is necessary to pay attention to the periodontal health of elderly diabetic patients and carry out targeted oral health care.