Diabetes and Gum Disease: What the Evidence Shows
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Key facts
In 35 trials with 3,249 people, treating gum disease lowered HbA1c by 0.43 percentage points at 3–4 months compared with no or delayed treatment.
Moderate-certainty evidence at 3–4 months; fewer studies at later time points.
A two-way relationship
High blood sugar makes gum infections more likely and more severe. In turn, the ongoing inflammation of gum disease is thought to make blood sugar harder to control. That is why diabetes care teams increasingly ask about the mouth.
What the Cochrane review found
The review pooled 35 randomized trials with 3,249 people, almost all with type 2 diabetes. Professional gum treatment (cleaning below the gumline, sometimes with other measures) lowered HbA1c by 0.43 percentage points at three to four months compared with no or delayed treatment, rated moderate-certainty evidence. Fewer studies looked at six and twelve months, so longer-term effects are less certain.
HbA1c measures average blood sugar over about three months.
Why this matters in a hospital
- Many inpatients have diabetes, and an admission is a chance to ask about dental pain and gum health.
- Patients with poorly controlled diabetes are more vulnerable to serious infections, including dental ones.
- Discharge planning can include a dental referral alongside diabetes follow-up.
- Teledentistry can give care teams a dentist's view when no dentist is on site.
What families can do
- Ask whether your family member has dental pain, bleeding gums or loose teeth, and tell the care team.
- Bring dentures, toothbrushes and dental history to the hospital.
- Ask for a dental referral at discharge if gum problems are noted.
Frequently asked questions
Does gum disease cause diabetes?
The evidence shows they affect each other; it does not show that gum disease causes diabetes.
How much does gum treatment lower HbA1c?
About 0.4 percentage points at three to four months in the Cochrane review, on average.
Does treatment replace diabetes medication?
No. It is an addition to medical diabetes care, not a substitute.
Who should people with diabetes see for gum care?
A dentist or periodontist, ideally at regular visits.
Bring dental care into diabetes care.
Please do not include patient information.
Sources
- Cochrane Review (Simpson et al., 2022): Treatment of Periodontitis for Glycaemic Control in People with Diabetes Mellitus
- Healthy People 2030 evidence summary: Treatment of Periodontitis for Glycaemic Control in People with Diabetes Mellitus
- National Institute of Dental and Craniofacial Research: Oral Health in America (2021)