Diabetes and the periodontal patient

It is now well known in the health professions and in the general media that diabetes is one of the major public health concerns in the United States. While the general prevalence of Type I (insulin dependent) diabetes has remained essentially stable over the past several decades, the incidence and prevalence of Type II (non insulin dependent) diabetes has steadily risen, with 20-25 million Americans now affected.  This is  argely because of changes in dietary habits, with an accompanying rise in obesity, which is a major risk factor for Type II diabetes. 

While Type II diabetes has been characterized by a later onset in life, more recently, there has been an alarming increase in Type II diabetes in children, and that partially can be attributed to an increase in childhood obesity.  Currently, while the prevalence of Type I diabetes is approximately 5% of all diabetes cases, the prevalence of Type II diabetes is about 95%.  This dramatic increase in diabetic patients has had a major impact on dental practice, particularly when it comes to diagnosing and treating periodontal diseases.   

A two-way relationship

The traditional view of diabetes and periodontal disease was as a “one-way” relationship in which poor glycemic control (blood sugar levels) in the diabetic patient went hand-in-hand with an increased severity of periodontal disease and with poorer responses to treatment.  Over the past decade there has been a decrease in the prevalence of more severe forms of periodontal diseases in the United States, in part because of decreased smoking rates and better public awareness. However, the increase in the numbers of Type II diabetics, and in particular the large proportion of Type II diabetics who are not aware of their condition and have poor glycemic control, gives one pause to consider the possibility of an increase in the incidence of periodontal diseases and their accompanying management issues in the near future.  Furthermore, over the past decade new insights have developed for the influence of periodontal diseases on the diabetic patient.  Specifically, as one of the most common inflammatory diseases and microbial infections, periodontal diseases may have a significant influence on a diabetic patient’s glycemic control (glucose levels).  Thus we have come to realize that the relationship between periodontal diseases and diabetes is a “two-way” relationship. 

This article briefly summarizes the impact of this two-way relationship, as well as future directions in understanding periodontal disease and diabetes.

The influence of diabetes on periodontal diseases

Regardless of whether the dentist is dealing with a diabetic patient with Type I or Type II diabetes, the levels of glucose and control of those levels of glucose is of critical importance for the influence of diabetes on periodontitis.  It is now well known that patients with either Type I or Type II diabetes have a 2.5-3.5 fold greater risk in developing periodontal diseases. This places diabetes as one of the major risk factors for the development of periodontal diseases. In addition the diabetic periodontal patient with poor glycemic control (a fasting glucose more than 125 milligrams per decaliter of blood, a non fasting glucose level more than 200 milligrams per decaliter of blood, and/or a glycosylated hemoglobin level of more than 8% of the total hemoglobin) will respond less favorably to the full range of periodontally related therapies, including subgingival debridement, soft and hard tissue periodontal surgery, and implants. 

The underlying reasons for this adverse effect of diabetes on periodontal tissues include an impaired ability to combat bacterial infection, an impaired wound healing, an impaired ability to regenerate tissue, an increase in destructive inflammatory substances in the response to infection, and perhaps most importantly,  the multiple damaging effects of the combination of glucose to a variety of proteins, termed advanced glycation end products (AGEs). These AGEs can cause local tissue damage by stimulating release of destructive inflammatory products, damaging the terminal circulation to the periodontal tissues, and stimulating alveolar bone resorption.  As similar mechanisms of damage occurs in other parts of the body, some now consider periodontitis the sixth cardinal sign of diabetes, which also includes vision loss, kidney failure, damage to the nervous system, cardiovascular diseases and general impaired wound healing.  

To prevent this chain of destructive periodontal events, it is important for the dental clinician to ensure the patient has acceptable glycemic control, particularly when performing the full range of periodontal procedures.

The influence of periodontal diseases on diabetes

In the diabetic patient, the presence of any chronic or acute infection and/or inflammatory disease can exacerbate the diabetic condition. Bacterial products and inflammatory products from diseased periodontal tissues can enter the bloodstream and induce greater insulin resistance in a variety of tissues in the body. With this impaired ability to respond to insulin to store glucose, periodontal diseases can further elevate levels of glucose and glycosylated hemoglobin. Additional support for the role of periodontal diseases in glycemic control comes from recent studies on the beneficial effects of a variety of periodontal treatments that reduce clinical periodontal inflammation, including debridement of bacterial deposits with or without antibiotics.  These studies have shown that such conventional periodontal treatments can lower levels of glycosylated hemoglobin by an average of approximately 0.8%.  While this number may not seem significant when compared with reductions in glycosylated hemoglobin with insulin injections for Type I diabetes, this improvement is comparable to reductions seen with many of the oral medications used in the treatment of Type II diabetes.

Future directions

While the appreciation of diabetes and periodontal diseases as a “two-way” relationship has been an important new development, with impact on all dental practices, there is probably more to this story. In particular, the mutual influence of obesity on both periodontal diseases and diabetes, making this a “three-way” relationship, has received considerable recent attention. All three conditions are linked by inflammation and infection.  With the increase of the prevalence of obesity in the United States, Type II diabetes, and combinations of these conditions into metabolic syndromes, the dental practitioner will continue to play a pivotal role in both the oral health of these patients, as well as the overall health of the patient.