The Connection Between Diabetes and Oral Health

By Mark Gurarie

Medically reviewed by Edmund Khoo, DDS

The elevated blood sugar levels resulting from diabetes can make it hard to maintain oral health. As a result, people with this condition are more prone to gingivitis and periodontitis (types of gum disease), halitosis (chronic bad breath), loss of teeth, dry mouth, and oral thrush (a fungal infection).1

This article explores the connection between diabetes and oral health, associated dental issues, and what you can do to prevent them.

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The Connection Between Diabetes and Oral Health

Diabetes can increase the chances of developing certain oral problems in several ways.

High glucose (sugar) in the blood also causes increased levels of sugar in saliva. The bacteria in plaque, the sticky film that builds up on teeth, feed on these sugars, which can cause tooth decay, cavities, and tooth loss, as well as raise the risk of periodontitis (gum disease).1

Furthermore, diabetes weakens the immune system, making it more difficult for infections to heal and to manage issues in the mouth. This, too, raises the risk of periodontitis and affects healing.2

Lastly, insufficient saliva production can be a side effect of certain diabetes medications. When your mouth is too dry, it’s less able to clear food particles from the mouth and stop bacteria from forming plaque, increasing the risk of tooth decay, cavities, and tooth loss.1

Types of Diabetes

Diabetes refers to multiple conditions impacting the body’s ability to break down sugars for energy. Most commonly, people have type 2 diabetes, in which there is insufficient uptake of glucose in cells causing an increased but inadequate production of insulin, the hormone that regulates blood glucose levels.

About 5% of people with diabetes have type 1 diabetes, caused solely by the body not producing enough (or any) insulin.3 Both types are associated with dental problems.

Oral Health Problems Associated with Diabetes

Diabetes can lead to and raise the risk of various dental health problems. Here are the most common issues people with diabetes should be aware of.

Dry Mouth

Diabetes is frequently accompanied by dry mouth, typically due to the side effects of the medications taken to manage it. This does so by reducing the amount of saliva produced, which can cause several specific issues, including:3

Halitosis, or chronic bad breath
A foul taste in the mouth
Difficulty swallowing (dysphagia) or chewing
Speech difficulties

In addition, since saliva plays a role in controlling bacterial spread in the mouth, a dry mouth raises the risk of gum diseases, cavities, tooth decay, and tooth loss.3

Tooth Decay

Tooth decay frequently accompanies diabetes. High glucose in the bloodstream increases the sugars in saliva, which feed the bacteria in the mouth. As a result, the level of acidity rises, which breaks down the hard enamel shells of the teeth. In turn, tooth decay leads to cavities and, if untreated, tooth loss.2

Tooth Loss as a Risk Factor

Tooth loss is much more common among people with diabetes than the population as a whole. In fact, people with diabetes can experience nearly twice as many missing teeth.3

Gingivitis

Gingivitis is a common and mild form of gum disease characterized by inflamed and bleeding gums. Dry mouth, high sugar levels in saliva, and decreased immune response associated with diabetes significantly increase the chances of developing this infection.3

Proper dental care and healthy habits can cure gingivitis, but if left untreated, it can cause more severe infections (periodontitis), tooth decay, bad breath, and other issues.

Periodontitis

Periodontitis is a severe gum infection and a complication of gingivitis. In addition to bleeding and swelling in the gums, this disease can cause pockets (known as abscesses) to form around the roots of teeth and surrounding bone. This can lead to loose teeth, chewing difficulties, and chronic bad breath and can damage underlying bone leading to tooth loss if it isn’t managed.2

Because high blood glucose also impacts the immune system, gum diseases, like periodontitis and gingivitis, are tougher to manage.1

Thrush

Oral thrush, also known as oral candidiasis, is a fungal infection of tissues in the mouth. It’s characterized by painful patches of white buildup on the tongue or inside the tissue lining of the oral cavity.2 This isn’t contagious and can be managed with antifungal medicine, but if left untreated, the fungus can spread to other parts of the body, leading to more severe complications.

Slow Wound Healing

Reduced immune function commonly accompanies diabetes, which can impact the mouth's health. When blood glucose levels are high and insulin is too low—common features of this condition—the body cannot produce enough cytokines.4

These proteins and lipids (fats) are essential for immune system signaling and function. In addition, diabetes hinders leukocytes (a blood cell that combats infection) and decreases the immune system's ability to recognize attacking bacteria, viruses, or fungi.

As a result, wound healing is hampered in those with diabetes. This makes it easier for gum disease to develop into periodontitis and allows cases to become more severe. This increases the chances of developing oral health problems like tooth decay and loss.1

Preventing Dental Issues

Given the close association between diabetes and oral health problems, dental care is critical if you have diabetes. Several strategies can help prevent issues from arising, including:2

Brushing your teeth with fluoride toothpaste for a minimum of 30 seconds per surface, for two minutes total, at least twice a day.
Flossing at least once a day.
Staying mindful and seeking help when you see signs of gingivitis or gum disease, such as bloody or swollen gums and loose teeth.
Using medication to manage your blood sugar levels.
Quitting smoking.
Letting your dentist know you have diabetes.
Seeking dental care and cleaning at least once every six months, possibly more often if your dentist recommends it.

Summary

Among the many negative health impacts of diabetes is poor oral health. This disease can lead to gingivitis and periodontitis, tooth decay and loss, dry mouth, and oral thrush (a fungal infection on the tongue or inside of the mouth). In addition, oral problems can worsen because of diabetes' impact on immune system function.

Managing blood sugar levels, attending timely dental visits, adopting good oral hygiene habits, and quitting smoking can help prevent oral health problems from arising.2

Sources

Centers for Disease Control and Prevention. Diabetes and oral health.

National Institute of Dental and Craniofacial Research. Diabetes and oral health.

Borgnakke WS, Poudel P. Diabetes and oral health: summary of current scientific evidence for why transdisciplinary collaboration is needed. Front Dent Med. 2021;2:709831. doi:10.3389/fdmed.2021.709831

Berbudi A, Rahmadika N, Tjahjadi AI, et al. Type 2 diabetes and its impact on the immune system. Curr Diabetes Rev. 2020;16(5):442-449. doi:10.2174/1573399815666191024085838

Centers for Disease Control and Prevention. Periodontal disease.

Centers for Disease Control and Prevention. Your diabetes care schedule.

Additional Reading

Centers for Disease Control and Prevention. Diabetes and oral health.

National Institute of Dental and Craniofacial Research. Diabetes and oral health.