Cross-sectional associations of type 2 diabetes with oral conditions: results of the 6th German Oral Health Study (DMS • 6).

OBJECTIVES: This study aimed to investigate the cross-sectional associations between type 2 diabetes (T2D) and periodontitis, dental caries, and tooth loss, according to the glycemic control status, time from T2D diagnosis, and microvascular complications (MVCs) among participants in the 6th German Oral Health Study (DMS • 6). METHOD AND MATERIALS: Cross-sectional data was pooled from participants from the DMS • 6 cross-sectional and cohort components who completed questionnaires regarding their oral and general health behaviors. Information on self-assessed oral health was obtained from interviews. T2D was defined as self-reported diagnosis by a physician. Participants were categorized according to their last self-reported glycosylated hemoglobin (HbA1c) level, time from T2D diagnosis, and presence of MVCs. Probing depth (PD), clinical attachment level (CAL), and presence of coronal and root caries were assessed for all teeth except the third molars, and the number of missing teeth was recorded. RESULTS: T2D was diagnosed in 9.0% of individuals. Severe periodontitis was diagnosed in 16.0% and 5.6% of individuals with and without T2D, respectively. Participants with T2D were more frequently edentulous, had more missing teeth, had higher prevalence of coronal and root caries, and exhibited poorer oral hygiene and dental-care practices. Fully adjusted models revealed that the mean PD and mean CAL were both higher in individuals with T2D than in those without. Compared with participants without T2D, those with T2D were 1.89 times more likely to have worse periodontal status. Among individuals with T2D, HbA1c levels > 7% showed stronger associations with periodontal variables than HbA1c ≤ 7%. Moreover, individuals with poorly controlled T2D had a higher prevalence of root caries than those without T2D. No significant associations were observed between decayed, missing, or filled teeth, percentage of decayed and filled teeth, or self-assessed oral health. Importantly, effect sizes for all outcomes did not differ significantly according to the time from T2D diagnosis. CONCLUSION: Poorly controlled T2D significantly affects periodontal health. Therefore, future studies should focus on intensified screening for undiagnosed diabetes by the dental workforce and closer communication between various specialists. (Quintessence Int 2026;57(Suppl):S106-S116; doi: 10.3290/j.qi.b6955523).