Gum health in people with diabetes: impact on blood sugar levels

In a blog for people with diabetes, dentists and researchers Josh Twigg and Ambrina Qureshi explain the link between gum health and blood sugar levels and what the latest evidence shows about the impact of treating gum disease (periodontitis) on blood sugar levels.

Take-home points

People with diabetes are more likely to have gum disease (periodontitis) than people without diabetes New Cochrane evidence shows that if people with diabetes also have gum disease, treating the gum disease is likely to have a positive effect on blood sugar levels The National Institute for Health and Care Excellence (NICE) recommends routinely discussing the risk of gum disease  at yearly reviews


Dentists have known for some time now that people with diabetes are more likely to present with gum disease . In the last few years, more and more research has suggested that treating gum disease can also improve blood sugar levels. However, the research has been controversial at times, with some studies showing no major effect and others showing a large effect of treatment. In our Cochrane Review Treatment of periodontitis for glycaemic control in people with diabetes mellitus (updated in April 2022), we wanted to find out if treating gum disease in people with diabetes and gum disease would improve blood sugar levels. We’ll explain what we found. But first:

A bit more about gum disease and treatment

Treatment for gum disease can be done by a dentist or a dental hygienist/therapist, and is formed of two parts. Firstly, your dental care professional can show you the best way to clean the teeth (including in between the teeth), because any plaque on your teeth can make gum disease worse. Getting teeth perfectly clean can be much more difficult than it sounds! The dental team might also talk to you about any other lifestyle changes you can make to improve your gum health, such as support for quitting smoking. The second part of treatment involves deep cleaning of the gums, which is normally done with numbing injections to make sure you stay comfortable during the treatment. This uses special curved instruments that can clean under the gum line where you cannot reach with brushing, and can also remove any hard deposits (called calculus) from the teeth that get in the way of normal cleaning.

What we found out about gum health and blood sugar levels

 When we updated our Cochrane Review this year, there was new evidence that gave a clearer picture than when we last looked at this (2015). We looked for studies involving people with type 1 or type 2 diabetes, but all but one of the 35 studies included only people with type 2 diabetes and periodontitis, with a mix of good, fair and poor management of blood sugar levels, as measured by glycated haemoglobin (HbA1c) which is a measure of the average blood sugar over the past three months.

The studies compared gum disease treatment involving scaling and root planning or deep cleaning, sometimes with other gum treatments and/or information about cleaning teeth properly, with ‘no active treatment’, or with usual care.

We found that gum disease treatment is likely to reduce blood sugar levels, measured by HbA1c, in people with diabetes.

We found an absolute reduction of 0.43% in HbA1c  at 3 months, 0.30% at 6 months and 0.50% after one year of gum treatment in people with diabetes and gum disease. An absolute reduction of 0.50% means that if your average blood sugar was measured at 7 mmol/mol start of treatment, on average it would be around 6.5 mmol/mol after a year of treatment. As an added bonus, your gum health would be improved too!

Dentists can be part of your diabetes management team

One of the most important changes that our review has brought about is recognition in recently updated National Institute for Clinical Effectiveness (NICE) guidelines on management of both Type 1 and Type 2 Diabetes that gum disease is an important risk in people with diabetes. They recommend that the diabetes team should advise patients with diabetes of their increased risk of developing gum disease and encourage them to have regular oral health check-ups with the dental team. Because developing gum disease can worsen blood sugar control in people with diabetes, the guidelines also recommend that professional treatment of gum disease by the dental team is an important part of diabetes care.

How often people need to have dental check-ups is an area of uncertainty (see the blog Dental check-ups: how often is enough?), but you can discuss with your dentist how often you should see the dental team, based on your individual needs. People with diabetes are twice as likely to have gum disease compared to people without diabetes. Often, gum disease remains hidden until it becomes more severe, which might mean developing wobbly teeth, infections, gum recession or teeth being lost, as well as making treatment more difficult and potentially more expensive.

News is spreading about the link between gum health and diabetes, but there’s still a long way to go. We need to continue making better links between dental teams and diabetes teams. If you think the information in this blog might be important to you, ask your diabetes team and your dentist about gum health.

More information about maintaining healthy gums and teeth

The European Federation of Periodontology

References (pdf)

Join in the conversation on Twitter with @AmbrinaQuresh @CochraneUK or leave a comment on the blog.

Please note, we cannot give medical advice and do not publish comments that link to individual pages requesting donations or to commercial sites, or appear to endorse commercial products. We welcome diverse views and encourage discussion but we ask that comments are respectful and reserve the right to not publish any we consider offensive. Cochrane UK does not fact check – or endorse – readers’ comments, including any treatments mentioned.















Josh Twigg and Ambrina Qureshi have nothing to disclose.

Gum health in people with diabetes: impact on blood sugar levels by Josh Twigg

is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International

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