Study Shows That Interdental Cleaning Improves Glucose Control

A new study published in Diabetes Spectrum provides compelling evidence that interdental cleaning is associated with measurably better glucose control among adults with type 2 diabetes.¹ The findings underscore the growing recognition that oral hygiene practices may play an important role in reducing systemic inflammation and supporting improved metabolic outcomes.

The cross-sectional analysis examined 104 adults with type 2 diabetes, assessing oral hygiene behaviors alongside glycemic variability measured through continuous glucose monitoring. Researchers evaluated toothbrushing frequency, interdental cleaning habits, dental visit patterns, and markers of inflammation, including high-sensitivity C-reactive protein and tumor necrosis factor-α. Individuals who brushed their teeth more frequently tended to have lower body mass index, lower inflammatory markers, and more favorable kidney health indicators.

However, interdental cleaning emerged as the most consequential behavior associated with glucose control. Nearly half of participants reported performing interdental cleaning three or more times per week. This group demonstrated significantly lower fasting glucose, lower A1C, greater time in range, and lower glucose management indicator values compared with individuals who did not engage in interdental cleaning. These associations remained robust even after adjusting for age, inflammation levels, and other potential confounders. The results suggest that interdental cleaning may offer a distinct and measurable benefit for metabolic health.

The study also highlighted demographic and behavioral trends. More than 60% of participants reported regular dental visits, a rate higher than national benchmarks for adults in Japan. Similarly, rates of toothbrushing at least twice daily and weekly interdental cleaning exceeded previously reported averages for individuals with type 2 diabetes. The inclusion criteria, which required at least 15 remaining teeth, may have contributed to these elevated oral care habits.

Importantly, the number of remaining teeth was itself associated with metabolic indicators. Participants with 20 or more teeth had better glucose profiles, including higher time in range and lower glucose management indicator values. Reduced dentition may impair masticatory function and limit the intake of high-fiber foods, which are emphasized in dietary guidance for diabetes management. The study found a positive relationship between the number of remaining teeth and total dietary fiber intake, reinforcing the connection between oral condition, nutrition, and glycemic control.

Regular dental visits were also linked to lower fasting glucose levels, suggesting that undiagnosed or unmanaged oral health issues may adversely affect metabolic outcomes. Collectively, these findings underscore the importance of integrating oral hygiene and dental care into comprehensive diabetes management strategies.

Reference

1. Harada K, Maeda Y, Sekiguchi D, et al. Oral hygiene practices and glucose profiles assessed through continuous glucose monitoring in adults with type 2 diabetes. Diabetes Spectr. 2025;38:441-448.