A large-scale observational study to investigate the current status of diabetic complications and their prevention in Japan (JDCP study 6): baseline dental and oral findings.

Japan Diabetes Complication and Prevention prospective (JDCP) study was conducted to examine the association between glycemic control and oral conditions in a large database of Japanese patients with diabetes. It included a total of 6099 patients with diabetes (range, 40-75 years) who had been treated as outpatients between 2007 and 2009. The mean number of present teeth at baseline was 19.8 and women with type 2 diabetes had fewer teeth than men with type 2 diabetes. Within the previous year, 17% of all patients had lost teeth. At baseline, 32% had experienced gingival swelling, 69% had brushed more than twice a day, 37% had used interdental cleaning aids, and 43% had undergone regular dental checkups. Multiple logistic regression analysis indicated that type 1 patients with HbA1c ≥ 7.0% were at higher risk of having fewer than 20 teeth (odds ratio [OR] 2.38; 95% confidence interval [CI] 1.25-4.78), and type 2 patients with HbA1c ≥ 8.0% also were at high risk of having fewer than 20 teeth (OR 1.16; 95% CI 1.00-1.34), after adjustment for nine possible confounding factors. In conclusion, patients with diabetes were found to be at high risk of tooth loss, and the poorer the glycemic control, the higher the risk of tooth loss in these patients.