The oral complications of diabetes mellitus, particularly from poorly controlled disease, are numerous and devastating. They include xerostomia (dry mouth), an increased susceptibility to bacterial, viral, and fungal infections (oral candidiasis), poor wound healing, increased incidence and severity of caries, gingivitis, and periodontal disease, periapical abscesses, taste impairment, and burning mouth syndrome.

Periodontal disease is the most common oral complication of diabetes and has been labeled the “sixth complication of diabetes mellitus.” There is evidence that a history of chronic periodontal disease can disrupt diabetic control, suggesting that periodontal infections may have systemic repercussions. Although the exact nature of this complex relationship is not yet clear, it has been shown that dental infections in diabetics may exacerbate problems with metabolic control, leading to elevated blood sugar (hyperglycemia) and acidosis, the loss of teeth, and the inability to wear dental prostheses.

The dentist plays a pivotal role in managing the diabetic patient. As part of the health care team, along with the patient’s physician and nutritionist, the dentist’s goal is controlling the patient’s diabetes through prevention. The patient’s physical examination should therefore include an oral examination and the management plan should include consultation for dental services and dental hygiene. Oral exams should be provided every six months.

It is now well established that the control of blood sugar (glycemic control) is most critical in possibly preventing, or delaying progression of, systemic complications. Moreover, patients with marginal control, as opposed to tight control of their diabetes, are at higher risk of oral disease progression as well as systemic problems.

Accordingly, the dentist must motivate the patient to maintain glycemic control in order to minimize the occurrence of oral complications, and can assess this control in consultation with the patient’s physician. For example, glycosylated hemoglobin (HbA1c) values provide a marker for metabolic control over a three- to four-month period. The goal of medical therapy is to lower this value to less than 7.0%. Another parameter for assessing even tighter metabolic control, particularly in the management of type 1, or insulin-dependent diabetes, is testing the blood sugar level one hour after a meal (one hour postprandial glucose) to assure that it falls within an acceptable range. Type 1 diabetics test blood sugar at least two to four times a day with a glucometer. Such an aggressive approach has become a mainstay in the medical management of insulin-dependent diabetes, especially for patients controlled with an insulin pump. Walking this metabolic tightrope, however, is not without risks. The patient may fall into profound low blood sugar or hypoglycemia (insulin shock) while using multiple insulin injections or into severe hyperglycemia with ketoacidosis (diabetic coma) while using an insulin pump.

Steps the Dentist Should Take
There are important reasons why a dentist should consider purchasing a glucometer for his or her practice. In those patients with diagnosed diabetes, insulin shock or diabetic coma may be averted. Furthermore, if the diabetic patient has hyperglycemia, the dentist can consult with the patient’s physician to determine if antibiotics are needed or whether additional medication should be administered to the patient before and after surgery. Finally, testing patients’ blood sugar, particularly those with a family history of diabetes, or those with signs and symptoms suggestive of diabetes mellitus, would be an enormous public service. Patients who may have undiagnosed diabetes can then be referred to their physician for further evaluation.

The dentist must educate the patient on how to perform effective oral hygiene that includes flossing and brushing after every meal. For those patients wearing dentures, the dentist must inform them to clean dentures and perform oral hygiene daily (including brushing the tongue); to remove dentures at nighttime; and to notify the dentist if the denture is ill fitting or causes an irritation or injury. Given the increased risk for infection in diabetics, it is particularly important for the dentist to remove fibromas due to irritation or treat ulcers related to trauma from poorly fitting prostheses, as well as to treat traumatic ulcers with antibiotics to prevent secondary infections, especially in poorly or marginally controlled diabetics.

In addition, the dentist should be prepared to use behavior modification techniques. For example, since smokers with diabetes are five times more likely than non-smokers to have gingivitis, it is the dentist’s obligation to refer the diabetic patient to smoking cessation programs and to provide support and follow up. In consultation with the patient’s nutritionist, the dentist can also help develop an effective prevention plan, and can encourage the patient to eat healthful snacks that are low in sugar.

In the diabetic patient with xerostomia or reduced salivary flow, the risk progression for oral disease is moderate to high. Accordingly, the dentist can prescribe saliva substitutes to minimize discomfort, monitor for caries, periodontal, and oral fungal disease (candidiasis), and recommend the use of fluoride-containing mouth rinses and toothpaste.

Managing Oral Infections in the Diabetic Patient
As part of the health care team, along with the patient’s physician and nutritionist, the dentist’s goal is controlling the patient’s diabetes through prevention.

While the comprehensive management of oral infections in diabetic patients is beyond the scope of this article, some final comments on the treatment of common oral infections are in order. In general, well-controlled diabetics, type 1 (insulin-dependent) or type 2 (non-insulin dependent), may have no more significant risk for oral disease progression than their non-diabetic counterparts and, hence, can be treated similarly. The well-controlled diabetic generally does not require antibiotics following surgical procedures. However, the dministration of antibiotics following surgery is appropriate, particularly if there is significant infection, pain, and stress. Several published papers have reported an additional therapeutic benefit from tetracyclines, independent of their antimicrobial action, thereby adding another dimension to the therapeutic management of periodontal disease. Supportive periodontal therapy should also be provided at relatively close intervals (two to three months) because there is a persistent tendency to progressive periodontal destruction, despite effective metabolic control. It is also extremely important for the dentist to make sure that the patient maintains a normal, sound diet following surgery in order to avoid low blood sugar episodes (hypoglycemia) and to promote effective healing and repair.

Carious lesions may be managed differently in diabetics, depending primarily on the degree of the patient’s glycemic control. For example, a coronal carious lesion that has not yet penetrated dentin in a well-controlled diabetic may require no immediate intervention, whereas a similar lesion in a poorly controlled diabetic (moderate to severe hyperglycemia) may need immediate operative treatment, given its higher risk of progression. Oral candidiasis, an opportunistic fungal infection, is commonly associated with hyperglycemia and is a frequent complication of diabetes. The dentist therefore must carefully evaluate his or her choice of antifungal agents. Some of these drugs have a significant sugar content (e.g., Clotrimazole troches), whereas others (e.g., Ketoconazole) can cause liver damage and, therefore, require the dentist to monitor the patient’s liver function tests in consultation with the patient’s physician.

The author has had type 1, or insulin-dependent diabetes, for the past 31 years and, for the past two years, has been on the insulin pump. To date, he has had no significant complications from diabetes.