A large study led by researchers from the National Dental Centre Singapore (NDCS) on the strong connection between gum disease and diabetes, found that routine dental visits could play a crucial role in identifying undiagnosed diabetes and prediabetes, particularly in Asian populations.
Published in Nov 2024 in the Journal of Clinical Periodontology, the study titled “Identifying Undiagnosed Diabetes and Prediabetes in the Dental Setting in an Asian Population—A Clinical Risk Model” assessed over 1,000 patients at NDCS and found that nearly 1 in 7 had undiagnosed diabetes or prediabetes.
The research team led by Dr Chee Hoe Kit, Senior Consultant with the Department of Restorative Dentistry, Periodontics Unit at NDCS, developed a clinical risk model that combines common health indicators – body mass index (BMI), family history of diabetes, smoking status and an oral health diagnosis – severe periodontitis, —to help dental professionals identify patients who are at high risk of diabetes or prediabetes.
Key findings from the study include:
- About 1 in 7 people seeking dental care may unknowingly have prediabetes or diabetes.
- The study, one of the largest of its kind in Asia, was conducted between May 2016 and October 2019, which examined 1,074 patients aged 21 and above.
- Of the participants:
- 6.1% (65) of the periodontal disease patients were newly diagnosed with type 2 diabetes
- 7.7% (83) were found to be prediabetic
- Patients with Stage III/IV periodontitis, high BMI, a family history of diabetes, and smoking habits were significantly at risk of undiagnosed diabetes.
- The addition of oral health indicator to traditional risk factors improved the accuracy of diabetes risk prediction.
Dr Chee highlighted four key risk indicators dentists can use to screen for potential diabetic patients:
- High BMI
- Family history of diabetes
- Tobacco-smoking
- Severe gum disease (Stage III/IV periodontitis)
Compared to people without diabetes, diabetic patients are more susceptible to periodontal disease because of poor blood sugar control, prolonged high levels of blood sugar, and an altered immune response, which together cause greater inflammation of the gums when it is infected with bacteria from the accumulation of dental plaque and tartar. Gingivitis, the initial form of gum disease, can worsen into periodontitis if left untreated. Periodontitis is categorised into four stages, with symptoms including frequent bleeding while brushing teeth, swollen gums, presence of pus exudate from the gumline, pain from the gums, shaky teeth, drifted teeth and widening gaps between teeth.
This research underscores the bi-directional co-relation between gum disease and diabetes – diabetes may worsen existing gum inflammation, while on the other hand, untreated severe gum disease can negatively affect blood sugar levels in diabetes patients, thus leading to poorer control of their existing diabetes condition. Therefore, the presence of severe gum disease might indicate undiagnosed diabetes in individuals who may not yet have developed other obvious signs and symptoms of diabetes.
The study also revealed the importance of interdisciplinary collaboration between dental and medical professionals to combat the growing diabetes epidemic, particularly in Asia where the burden of type 2 diabetes (T2D) is among the highest globally. The prevalence of diabetes (11.6%) in multi-ethnic Singapore ranks among the highest in Southeast Asia (International Diabetes Federation 2021) and is projected to increase to 23% in 2035.
“Our findings mirror the prevalence of undiagnosed diabetes in Singapore[1] and highlight the untapped potential of dental clinics as frontline settings for early diabetes detection,” said Dr Chee. “Given the strong link between periodontal disease and diabetes, dentists are uniquely positioned to identify at-risk individuals and refer them for timely medical evaluation.”
NDCS aims to educate its patients and the general public about the connection between gum health and diabetes. As gum disease is an oral health complication of diabetes, NDCS runs a clinical dental service in the Diabetes & Metabolism Centre (DMC) to screen diabetes patients for gum disease and to treat their gum condition accordingly, in collaboration with SGH.
Through the DMC collaboration, a long term study (published recently in Sept 2025 in the Journal of Dental Research) was conducted on 154 non-smoking T2D patients with periodontitis who underwent nonsurgical periodontal therapy (NSPT), including personalised oral health instruction and dental check-ups with supportive periodontal care at 3-month intervals for a year-long study. NDCS researchers found that active periodontal treatment followed by regular maintenance not just showed significant improvements in gum health, including reduced inflammation and bleeding, but that it led to a sustained reduction in HbA1c levels — a key marker of long-term blood glucose — by up to 0.77% overall, and 1.31% in patients with poor glycemic control (HbA1c > 8.0%). The study is one of the first to account for changes in diabetes medication and track HbA1c trends up to 12 months before and after periodontal treatment was instituted.
“Our findings support a collaborative medical-dental approach. Periodontal therapy not only improves oral health but also contributes meaningfully to better diabetes outcomes.” adds Dr Chee Hoe Kit.
With diabetes and periodontitis affecting over a billion people globally, this research highlights a cost-effective and non-pharmacological strategy to enhance metabolic control and reduce complications in people living with diabetes.
