Nonsurgical Periodontal Therapy Helps Improve Blood Sugar Control in Type 2 Diabetes, Study Finds

Netherlands: A new longitudinal study published in the Journal of Dental Research has found that nonsurgical periodontal therapy (NSPT) not only improves gum health but also significantly lowers blood sugar levels in patients with type 2 diabetes (T2D), particularly in those with poor baseline glycemic control.
The research, led by H.K. Chee from the Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Netherlands, explored the long-term effects of periodontal treatment on HbA1c levels while accounting for changes in diabetes medications—an aspect that many earlier short-term studies overlooked.
The study followed 154 nonsmoking patients with T2D and periodontitis who received NSPT. Treatment involved professional plaque removal, subgingival instrumentation, root surface debridement, and oral hygiene instructions at baseline, with maintenance care and repeated subgingival therapy provided at 3, 6, 9, and 12 months. Full-mouth periodontal assessments were conducted at each follow-up, measuring plaque accumulation, bleeding on probing, gingival suppuration, attachment loss, and periodontal inflamed surface area (PISA). Glycemic control was tracked through point-of-care HbA1c testing at each visit, supplemented with HbA1c records from the year preceding treatment.
At baseline, the average HbA1c level was 8.4% ± 1.6%. Following treatment, participants demonstrated consistent and sustained improvements in glycemic control. HbA1c decreased by 0.70%, 0.73%, 0.68%, and 0.77% at 3, 6, 9, and 12 months, respectively. Notably, those with poorer baseline control (HbA1c >8.0%) experienced the greatest improvement, with an average 1.31% reduction at 12 months compared to just 0.24% in patients who began with HbA1c ≤8.0%.
Periodontal health also showed marked improvement over the study period. PISA was reduced by 352.7 mm² after 12 months, while clinical attachment loss, probing pocket depth, and bleeding scores all significantly improved by the three-month follow-up and were sustained through the year.
Key Findings
- Average HbA1c dropped by about 0.7% at 3, 6, 9, and 12 months after periodontal treatment.
- Patients with baseline HbA1c >8.0% showed the greatest benefit, with a 1.31% reduction at 12 months.
- Periodontal inflamed surface area (PISA) decreased by 352.7 mm² after 12 months.
- Clinical attachment loss, probing pocket depth, and bleeding scores improved at 3 months and were sustained throughout the year.
“These results highlight the important systemic benefits of periodontal therapy beyond oral health alone,” the authors noted. “Nonsurgical periodontal treatment, when combined with ongoing maintenance, can play a valuable role in improving metabolic control among individuals with type 2 diabetes.”
The findings support the growing evidence of a strong link between periodontal disease and systemic health outcomes, suggesting that managing gum inflammation may have significant implications for diabetes care. While the study was observational, the results align with clinical insights that addressing chronic inflammation through periodontal care can improve glycemic outcomes.
“NSPT led to lasting improvements in both periodontal status and glycemic control over 12 months in patients with T2D. The benefits were especially pronounced in those with poor initial diabetes control, underscoring the importance of integrating oral health care into comprehensive diabetes management strategies,” the authors concluded.
Reference:
Chee, H. K., Tan, H. X., Tjakkes, H. E., Vissink, A., & Seneviratne, C. J. Long-Term Effect of Periodontal Therapy on HbA1c Changes in Type 2 Diabetes. Journal of Dental Research. https://doi.org/10.1177_00220345251357875
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