How Does Diabetes Affect the Mouth?

People who have diabetes know the disease can harm the eyes, nerves, kidneys, heart and other important systems in the body. Did you know diabetes can also cause problems in your mouth?

People with diabetes are at special risk for periodontal (gum) disease, an infection of the gum and bone that hold the teeth in place. Periodontal disease can lead to painful chewing difficulties and even tooth loss. Dry mouth, often a symptom of undetected diabetes, can cause soreness, ulcers, infections, and tooth decay. Smoking makes these problems worse.

What can I do?

Good blood glucose control is key to controlling and preventing mouth problems. People with poor blood glucose control get gum disease more often and more severely than people whose diabetes is well controlled. Daily brushing and flossing, regular dental check-ups and good blood glucose control are the best defense against the oral complications of diabetes.

What happens if I have plaque?

Plaque that is not removed hardens over time into tartar and collects above your gum line. Tartar makes it more difficult to brush and clean between your teeth. Your gums become red and swollen, and bleed easily—signs of unhealthy or inflamed gums, called gingivitis.

When gingivitis is not treated, it can advance to gum disease called periodontitis. In periodontitis, the gums pull away from the teeth and form spaces, called pockets, which slowly become infected. This infection can last a long time. Your body fights the bacteria as the plaque spreads and grows below the gum line. Both the bacteria and your body’s response to this infection start to break down the bone and the tissue that hold the teeth in place. If periodontitis is not treated, the gums, bones, and tissue that support the teeth are destroyed. Teeth may become loose and might need to be removed. If you have periodontitis, your dentist may send you to a periodontist, an expert in treating gum disease.

How will I know if I have mouth problems from diabetes?

Check your mouth for signs of problems from diabetes. If you notice any problems, see your dentist right away. Some of the first signs of gum disease are swollen, tender, or bleeding gums. Sometimes you won’t have any signs of gum disease. You may not know you have it until you have serious damage. Your best defense is to see your dentist twice a year for a cleaning and checkup.

How can I prepare for a visit to my dentist?

Plan ahead. Talk with your doctor and dentist before the visit about the best way to take care of your blood glucose during dental work.

You may be taking a diabetes medicine that can cause low blood glucose, also called hypoglycemia. If you take insulin or other diabetes medicines, take them and eat as usual before visiting the dentist. You may need to bring your diabetes medicines and your snacks or meal with you to the dentist’s office.

You may need to postpone any nonemergency dental work if your blood glucose is not under control.

If you feel nervous about visiting the dentist, tell your dentist and the staff about your feelings. Your dentist can adapt the treatment to your needs. Don’t let your nerves stop you from having regular checkups. Waiting too long to take care of your mouth may make things worse.

How does smoking affect my mouth?

Smoking makes problems with your mouth worse. Smoking raises your chances of getting gum disease, oral and throat cancers, and oral fungal infections. Smoking also discolors your teeth and makes your breath smell bad.

Smoking and diabetes are a dangerous mix. Smoking raises your risk for many diabetes problems. If you quit smoking,

  • you will lower your risk for heart attack, stroke, nerve disease, kidney disease, and amputation
  • your cholesterol and blood pressure levels might improve
  • your blood circulation will improve

If you smoke, stop smoking. 

How can I keep my mouth healthy?

You can keep your mouth healthy by taking these steps:

  • Keep your blood glucose numbers as close to your target as possible. Your doctor will help you set your target blood glucose numbers and teach you what to do if your numbers are too high or too low.
  • Eat healthy meals and follow the meal plan that you and your doctor or dietitian have worked out.
  • Brush your teeth at least twice a day with fluoride toothpaste. Fluoride protects against tooth decay.
    • Aim for brushing first thing in the morning, before going to bed, and after each meal and sugary or starchy snack.
    • Use a soft toothbrush.
    • Gently brush your teeth with the toothbrush angled towards the gum line.
    • Use small, circular motions.
    • Brush the front, back, and top of each tooth. Brush your tongue, too.
    • Change your toothbrush every 3 months or sooner if the toothbrush looks worn or the bristles spread out. A new toothbrush removes more plaque.

  • Drink water that contains added fluoride or ask your dentist about using a fluoride mouth rinse to prevent tooth decay.
  • Ask your dentist about using an anti-plaque or anti-gingivitis mouth rinse to control plaque or prevent gum disease.
  • Use dental floss to clean between your teeth at least once a day. Flossing helps prevent plaque from building up on your teeth. When flossing,
    • slide the floss up and down and then curve it around the base of each tooth under the gums
    • use clean sections of floss as you move from tooth to tooth

  • Another way of removing plaque between teeth is to use a dental pick or brush—thin tools designed to clean between the teeth. You can buy these picks at drug stores or grocery stores.
  • If you wear dentures, keep them clean and take them out at night. Have them adjusted if they become loose or uncomfortable.
  • Call your dentist right away if you have any symptoms of mouth problems.
  • See your dentist twice a year for a cleaning and checkup. Your dentist may suggest more visits if you need them. 
  • Follow your dentist’s advice.
    • If your dentist tells you about a problem, take care of it right away.
    • Follow any steps or treatments from your dentist to keep your mouth healthy.
  • Tell your dentist that you have diabetes.
    • Tell your dentist about any changes in your health or medicines.
    • Share the results of some of your diabetes blood tests, such as the A1C test or the fasting blood glucose test.
    • Ask if you need antibiotics before and after dental treatment if your diabetes is uncontrolled.
  • If you smoke, stop smoking.

Diabetes causes its own problems

Plaque is the “bad guy” of gum disease. But things are not helped by your diabetes. This is because:

  • Diabetes can weaken your mouth's germ fighting powers.
  • High blood glucose levels can make gum disease worse.
  • Diabetes may cause damage to the blood vessels supplying your gums.

If you have an infection from gum disease this can make your diabetes harder to control (usually causing your blood glucose levels to go up).

Warning signs of gum disease

Because gum disease is often painless, you may not know you have a problem until you have some serious damage. Regular check-ups at your dentist are your best weapon, but you can also help prevent it from happening by looking out for the early warning signs of gum disease. These are:

  • Bleeding gums when you brush or floss. Bleeding from your gums is not normal. Even if your gums don't hurt, get them checked
  • Red, swollen, or tender gums
  • Gums that have pulled away from your teeth. Part of the tooth's root may show, or your teeth may look longer
  • Pus between your teeth and gums (when you press on the gums)
  • Bad breath
  • Adult teeth that are loose or moving away from each other
  • Changes in the way your teeth fit when you bite
  • Changes in the fit of partial dentures or bridges

If you have any of the above, visit your dentist as soon as possible.

Brush and floss

The three main steps to fight gum disease are brushing, flossing, and seeing your dentist regularly. Brush twice a day and floss at least once a day. Ask your dentist to show you the correct way to brush and floss. Here are some tips.


A toothbrush can only clean one or two teeth at a time. Allow about 3 minutes of brushing to clean all your teeth well.

  • Use a brush with soft bristles and rounded ends. Soft bristles are less likely to hurt your gums.
  • Angle the brush to the gum line, where teeth and gums meet.
  • Move the brush back and forth with short strokes. Use a gentle, scrubbing motion.
  • Brush the outside surfaces of the teeth. Do the same for the backs of teeth and chewing surfaces.
  • Lightly brush the rough surface of your tongue to remove germs and freshen your breath.
  • Brush your gums too.
  • Get a new toothbrush when the bristles are worn or bent (about every 3 to 4 months).


Few people really enjoy flossing. But if you don't floss, you're only doing half the job of cleaning your teeth and gums. Flossing cleans away plaque and bits of food from between your teeth and below the gum line. It gets places your brush can't reach. Floss once a day.

  • Break off about 18 inches of floss and wind most of it around one of your middle fingers. Wind the rest around the same finger of the other hand.
  • Hold the floss tightly between your thumbs and index fingers. Leave about an inch of floss between them.
  • Use a gentle sawing motion to get the floss between your teeth. Never snap the floss into the gums (this can cut your gums).
  • When you get the floss to the gum line, curve it into a C-shape against one tooth. Scrape up and down on the sides of each tooth to remove plaque.
  • As floss gets worn and dirty, move to a clean section and continue. Don't forget the backsides of your rear teeth.
  • When you're finished brushing and flossing, rinse your mouth with water.
  • If you have arthritis in your hands, trouble moving your fingers, or bridgework in your mouth, a floss holder might help. Ask your dentist about ways to make flossing easier for you.

Oral Infections

An oral infection is a cluster of germs causing problems in one area of your mouth. Here are some warning signs.

  • Swelling or pus around your teeth or gums or any place in your mouth. Swelling can be large, or as small as a pimple.
  • Pain in the mouth or sinus area that doesn't go away.
  • White or red patches on your gums, tongue, cheeks or the roof of your mouth.
  • Pain when chewing.
  • Teeth that hurt when you eat something cold, hot or sweet, or when you chew.
  • Dark spots or holes in your teeth.

Infections can make your blood sugar hard to control. By planning ahead and discussing a plan of action with your dentist and doctor, you will be prepared to handle needed adjustments.

Fungal Infections

Having diabetes means you are more prone to fungal infections such as thrush. If you tend to have high blood sugar levels or take antibiotics often, you are even more likely to have this problem. Thrush makes white (or sometimes red) patches in areas of your mouth. These can get sore or turn into ulcers.

Thrush likes moist spots that may be chafed or sore, for example, under poorly fitting dentures. Smoking and wearing dentures all day and night can increase the risk of thrush. Quitting smoking and limiting the time dentures are worn can reduce the risk of getting thrush. If you think you have a fungal infection, talk to your dentist or doctor.

Poor Healing

If your diabetes is poorly controlled, you heal more slowly and you increase your chance of infection after dental surgery. To give yourself the best shot at healing well, keep your blood sugar under control before, during, and after surgery.