Diabetes and Oral Health

By Shannon Waldron, Registered Dental Hygienist posted in Healthy Living Professionals & Educators


Introduction: Diabetes and Oral Health

We tend to associate tooth decay and periodontal disease with too much sugar and not enough brushing and flossing.  While we know that what we eat and drink can affect oral health there are many other things including diabetes, some medications and medical therapies that can negatively impact one’s overall oral health.

All forms of diabetes can result in similar conditions of hyperglycemia or high blood sugar. Instability of blood sugar can also result in hypoglycemic reactions or low blood sugar. This is a medical emergency which can be treated with juice or another form of sugar. Prolonged uncontrolled Diabetes can cause eventual damage to the kidney, nerves, eyes, heart disease or blood vessels. (1)

Oral Health Complications

There are also many complications that are directly related to oral health. Some of these are oral infections, halitosis (bad breath), salivary gland dysfunction, taste disturbances, burning mouth syndrome, recurrent aphthous stomatitis, lichen planus, and oral pre-malignancies. More commonly seen adverse effects are oral fungal infections such as yeast infections in the mouth, increased caries, gingivitis, and bone loss associated with periodontal disease. (4,5)


Gingivitis is the condition of inflammation of the gums. It can be completely reversed through proper brushing, flossing, and sometimes dental hygiene treatment such as scaling and root planning. Periodontal disease is a condition in which this inflammation leads to more inflammation, pocketing and bone loss. This bone loss is not reversible and can only be maintained to prevent it from getting worse. Maintenance includes regular dental hygiene treatment of scaling and root planning.

Periodontal Disease

Individuals with diabetes are approximately 3 times more prone to destructive periodontal disease. (6–8) More specifically, evidence has been provided since the 1960’s to show that patients with poorer glycemic control demonstrate an increase in the severity of periodontal disease. (2,7,9,10)

Current research has examined the idea of a “bidirectional relationship” between periodontal disease and elevated blood sugars. (4,7,11–13) A bidirectional relationship means that not only are individuals with diabetes prone to periodontal disease, but also that periodontal disease can have adverse effects on glycemic control. A large scale systematic review of 690 articles concluded that there is a statistically significant reduction in HbA1c after Dental Hygiene Therapy was completed.(14) This is because of the predominance of harmful bacteria and inflammatory mediators that are present in periodontal infections. These mediators interfere with glucose and lipid metabolism as well as antagonize the individual’s insulin action.(2,11,14)

The aim of current periodontal therapy is to reduce the number of pathogens from the infected periodontium and to remove deposits which encourage microbial colonization.  Due to the transient nature of bacteria, it becomes more damaging after 90 days. Therefore, it is recommended that individuals with diabetes and periodontal disease receive dental hygiene therapy at 3 month intervals. (15,16)

Dental Decay

Increased risk for dental decay is also a multifaceted problem in individuals with diabetes. Caries, more commonly known as cavities, can be caused by the side effects of medications, xerostomia (dry mouth) due to poor metabolic control. Excess glucose has been found to enter the mouth through saliva and gingival crevicular fluid, however the extent to which this plays a role in the increase of caries formation is still uncertain.  (17–20)  What is agreed upon however is that individuals with diabetes create a sugar rich, under-cleansed oral environment for bacterial plaque and fungus to thrive.

Oral Candidiasis


Thrush is another term for an oral yeast infection or Pseudomembranous candidiasis. This opportunistic fungal infection is known to target individuals that are immunocompromised including individuals that are iron deficient, individuals with carbohydrate-rich diets and individuals with diabetes. (20,21) It is characterized by a whitish membrane on the surface of the oral mucosa or tongue. It is often identified by an attempt to rub of this “milk curd” like lesion, in which it will reveal a raw, red, and often bleeding base. It can be treated with the use of antifungal drugs, such as nystatin (similar to the treatment for vaginal yeast infections) and is given in the form of pastilles or lozenges. (21)

Patient Perceptions

Addressing the relationship between diabetes and oral health may improve the oral health, quality of life and the risk of diabetic complications. Research has demonstrated that there was little awareness and understanding about the relationship between oral health and diabetes amongst the patient population.(4,5) It was reported that the largest barrier to oral health care was the limited access due to the additional expenses of diabetes care.(4)

The main reasons cited for not visiting the dental office are a perceived lack of need, cost, and finding dental visits unpleasant. Oral self-care was also rated as less important than other diabetes self-care tasks including regular foot checks and eye exams. Awareness of tender swollen gums and tooth loss is not thought to be important to patients. (5)

Due to the lack of dental coverage in a population in which a disproportionate health burden falls, it has been suggested that a focus on prevention from front line providers such as health educators, doctors and nurses could reduce the oral healthcare complications of diabetes. (4)

The gap in the awareness and knowledge about the relationship between oral health and diabetes is present in patients as well as medical health professionals.

Health Professionals Roles

Since Dental Hygiene Therapy has a positive impact on individuals with diabetes it should be incorporated into the standard measures for diabetes care. Dental Hygienists, Periodontists, and Dentists must work together as a team to establish rigorous metabolic control of diabetes in their patients.(22)

69% of patients have reported that they had never received any oral health education specifically related to their diabetes care from any health professional. Only 30% of patients stated that they had talked to their dentist about their diabetes, and only 10% had been told by any health professional to see a dental hygienist regularly.(4,5)

Clear communication between all health providers regarding daily disease management needs to occur. Bowyer reported that patients are not encouraged to discuss oral health issues related to diabetes with their oral health professionals. This may be due to a lack of training and education for health professionals to explain the importance of regular health check-ups

Close collaboration between oral health professionals, medical professionals and policy makers has been recommended by both the FDI World Dental Federation and the International Diabetes Federation. Several organizations have recommended promotion of oral health and increasing awareness of oral disease, including routine oral screening of individuals with diabetes.


Due to the role that oral health plays in the prevention of diabetes complications, it is necessary that the interdisciplinary team collaborates with individuals with diabetes to safeguard oral health. It is jointly required that oral health professionals consider their role in improving the quality of life and management of diabetes. In order to facilitate these outcomes continuing education and training that underscores the bidirectional relationship between diabetes and oral health, strategies for interdisciplinary care and improved communication between care providers, and the promotion of health information related to oral health complications is essential.


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Shannon has been a Registered Dental Hygienist for 12 years. She graduated from George Brown College with honors in 2001. She began her career in Ontario and currently holds the 365 day rule exempt status in British Columbia where she practices today. She is also currently teaching at the University of British Columbia as a Dental Hygiene Instructor and is a member of the Canadian Dental Hygienists Association. Shannon obtained her BDSc in Dental Hygiene, from UBC and received the 2010 BCDHA Joan Voris Award of Achievement for Educational Vision. She is also the recipient of the 2012 Hu-Friedy/CDHA Nevi Scholarship. Shannon is currently a Master of Craniofacial Science and pursuing research in the area of Competency Based Education. She has published in the Canadian Journal of Dental Hygiene and is in final stages of preparation for 3 other articles based on her research. Shannon was diagnosed with type 2 diabetes MODY (Mature Onset Diabetes of the Young) when she was 15 years old. As is customary with this variety of diabetes, she also has a parent (mother) with type 1 diabetes and a grandmother with type 2 diabetes. She has also experienced gestation while being dependent on insulin, and is now the mother of 3 school age girls. Shannon’s personal experience with diabetes has led her to research diabetes and oral health care at several points in her academic career. She has often reflected on the minimal knowledge and awareness that is held by her colleagues and health care providers. This is something she one day hopes to impact in her career as an academic.