Dental health

The mouth is often overlooked as an area of the body with complications associated with diabetes.

The most commonly recognised oral complication related to diabetes is periodontitis (advanced gum disease).

Other oral complications can include:

  • Dental caries (tooth decay)
  • A decrease in saliva production causing a dry mouth (xerostomia)
  • Oral thrush (fungal infection)
  • Delayed or poor healing of wounds in the mouth, such as mouth ulcers
  • Altered taste


Periodontitis is a chronic disease that requires life-long care and professional treatment. It causes recession of the gum and/or bone surrounding affected teeth. These changes are irreversible. A dentist or periodontist (gum specialist) can check for signs of periodontal disease and provide treatment. Severe untreated disease can result in teeth becoming loose, painful and eventually being lost.

The risk of developing periodontitis is greater in people with diabetes, particularly when blood glucose levels are not within the recommended range of 4-7 mmol/L. However, with optimum blood glucose management the risk of developing periodontitis is the same as for a person without diabetes.

There is increasing evidence of a two-way relationship between periodontitis and diabetes.

Periodontitis may negatively affect blood glucose levels. Studies have shown that people with periodontitis exhibit a higher chance of developing prediabetes and diabetes. People with periodontitis have poorer glycaemic status (higher level of HbA1C), compared to people without periodontitis.

Professional periodontal treatment has been shown to create a mild improvement in blood glucose levels. However, these results lasted for only a short three-month period of time (longer term studies are ongoing).

These relationships can differ for people with type 1 diabetes compared to type 2. It is important that people continue to remain in control of their oral health and their diabetes management over time.

Tooth decay

The root of a tooth anchors the tooth in the mouth and is covered by the bone and gums. Periodontitis can cause the bone and gum around the tooth to recede. This uncovers and exposes the root surface, which is not as strong as the white enamel covering the tooth crown.

Decay of the tooth’s root surface can occur more often in people with diabetes. This decay is influenced by factors associated with diabetes including gum recession from periodontitis exposing the root surface and a decrease in saliva flow. Saliva helps to protect the teeth against decay, therefore, a decrease in saliva can cause a person to become more prone to decay.

Xerostomia (Dry mouth)

People with diabetes more commonly experience a decrease in saliva production which can cause a dry feeling within the mouth. This is reported to be more common in patients with diabetes complications, in particular diabetic neuropathy.

Oral thrush

Oral thrush is an oral fungal infection, often called oral candidiasis (caused by Candida bacteria). It appears as creamy white patches in the mouth, often on the tongue or inside of the cheeks. It can occur in people with diabetes due to multiple reasons:

  • A decrease in saliva being produced
  • High blood glucose levels cause increased glucose in saliva which can cause more Candida bacteria to live and grow.
  • A poor immune system

Delayed or poor wound healing

Due to changes in blood flow and a poorer body immune system in people with diabetes, this can cause delayed healing of wounds in the mouth.

Altered taste

The ability to taste foods and drinks can be affected in people with diabetes. The underlying cause for this is not clear. It may be related to the taste receptors in the mouth renewing at a slower rate or is suggested to be associated with the presence of diabetic neuropathies.

Disease symptoms

Diabetes can lead to multiple complications in the mouth. These complications can increase in severity when a patient has poor control of their blood glucose levels. Patients with complications of diabetes, particularly diabetic neuropathy, can be more likely to develop oral complications.

Signs of periodontal disease can include bleeding from gums, bad breath, sensitive teeth, loose teeth, recession of the gums (or longer looking teeth) and gaps developing between the teeth which may lead to food becoming stuck.

You may think you do not have any of the listed conditions because you are not experiencing any pain or discomfort. Many of these diseases are often painless, however, in cases of advanced disease or sudden flare-up, pain can occur. At this stage, it may be too late for treatment to save the tooth. This shows why it is important to look after your oral health.

Looking after your oral health

To look after your oral health and decrease the risk of complications:

Brush your teeth twice-a-day using a soft toothbrush with a pea-size amount of fluoride-containing toothpaste

  • Fluoride combines with the white enamel surface of the teeth to strengthen the tooth structure and prevent tooth decay.

Clean between your teeth daily using floss or interdental brushes

  • Ask your dentist if interdental brushes can help you in caring for your teeth and gums. These brushes look similar to a toothpick but have bristles at the end to clean away food and bacteria when placed in the spaces between the teeth.

Eat a diet low in sugar

Drink fluoridated tap water where available

  • Water fluoridation is the safest and most effective way to reduce tooth decay. It has been shown to reduce tooth decay by 26% to 44% in children and adolescents, and by 27% in adults.

Chewing sugar-free gum can help to stimulate saliva flow

See a dentist regularly for a check-up of your teeth and gums. The dentist will advise you how often to return for check-ups and treatment. This may be more often if you have any of the above complications from diabetes. Oral health education should be provided to all patients with diabetes.

Avoid smoking

  • Other than diabetes, cigarette smoking is another important risk factor for developing periodontitis. If you are a current or previous smoker, it is recommended you tell this to your dentist.

After treating hypoglycaemia with fast acting carbohydrates, such as jellybeans, soft drink, fruit juice or sugar directly, drinking water once you feel well again helps to rinse the sugar and acids from your mouth. If you would like to brush your teeth, try to wait 60 minutes before doing so.

Who can help you care for your oral health?

Your general dentist can help you in caring for your oral health. In cases of advanced periodontitis, specialist referral to a periodontist (gum specialist) may be beneficial.

It is important to tell your dentist if you have diabetes and how well the condition is controlled. Ensure your dentist knows the names of all prescribed and over-the-counter tablets and medicines you take as well as if you are a current or past smoker.

For more information: contact the Australian Dental Association.

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