Dental Service Use during the 30 Years before Type 2 Diabetes Onset

Although the association between type 2 diabetes mellitus (T2DM) and oral disease has been widely investigated, little is known about long-term dental care patterns before T2DM diagnosis. This study therefore described dental service utilization up to 30 y prior to the incidence of a T2DM, compared with age- and sex-matched controls. This matched cohort study used nationwide Danish registry data on individuals born between 1950 and 1970 who maintained permanent residency from 1990 to 2021. For each person with incident T2DM in 2021, 4 age- and sex-matched controls were selected. Incident T2DM was identified based on the purchases of glucose-lowering medication or a hospital diagnosis. Dental service utilization included receipt of any dental care, periodontal, endodontic, restorative, and extraction treatments. Time trends were analyzed using logistic and Poisson regression models. Among 1,231,846 eligible individuals, 10,205 had incident T2DM in 2021 and were matched to 40,820 controls. The incident T2DM population was less likely to receive dental care in a calendar year than the controls and had 2.4 (95% confidence interval [CI]: 2.2 to 2.6) fewer years with a dental visit in the years preceding the diagnosis. The individuals with incident T2DM were more likely to have received periodontal (risk ratio: 1.08, 95% CI 1.05 to 1.12) and endodontic treatments (risk ratio: 1.14, 95% CI: 1.11 to 1.17), and they had received more extractions (rate ratio: 1.32, 95% CI: 1.29 to 1.36) and slightly more restorative treatments (rate ratio: 1.02, 95% CI: 1.00 to 1.04) during a calendar year over the period preceding the T2DM diagnosis than did the controls. More than 30 y prior to diagnosis, individuals who developed T2DM were less likely to attend dental care, but when they did attend, they underwent more complex and invasive procedures. These findings support a common risk factor approach to prevent T2DM and oral diseases at the clinical, health system, and policy levels.