Diabetes mellitus is a complex disease with varying degrees of systemic and oral complications, depending on the extent of metabolic control, presence of infection and underlying demographic variables. This has led to conflicting results in epidemiological studies, with regard to periodontal disease presentation in diabetic patients and their response to treatment. This section deals with diabetes and its implications on the host response to bacterial plaque, in the context of clinical and laboratory data pertaining to periodontal disease.
Type 1 and Type 2 diabetes mellitus
Diabetes mellitus (DM) is categorized as Type 1 and Type 2 DM. Type 1 DM develops due to impaired production of insulin, while Type 2 DM is caused by deficient utilization of insulin. Type 1 DM results from destruction of the insulin producing [3-cells of the pancreas. This can occur when genetically predisposed individuals succumb to an inducing event such as a viral infection or other factors that trigger a destructive autoimmune response. Approximately 10-20% of all diabetics are insulin-dependent or Type 1. They usually have a rapid onset of symptoms associated with a deficiency or total lack of insulin and the condition may be difficult to control. Nearly 90% are diagnosed before the age of 21years.
Type 2 DM results from insulin resistance which also contributes to cardiovascular and other metabolic disturbances. However, insulin production may decrease later in the disease process and require supplementation, in addition to controlling diet or using oral hypoglycemic agents. The onset of symptoms in Type 2 DM is more gradual and less severe, usually presenting after the age of 40 years.
The typical signs and symptoms of diabetes are polyuria, polydipsia, polyphagia, pruritus, weakness and fatigue. These features are more pronounced in Type 1 than in Type 2 DM, and are a result of hyperglycemia. The complications of DM include retinopathy, nephropathy, neuropathy, macrovascular disease and impaired wound healing. In view of these findings, the treatment of DM is aimed at reducing blood glucose levels to prevent such complications.
There is conclusive evidence of the importance of glycemic control in the prevention of diabetic complications. Patients regularly use blood glucose monitors to provide effective feedback for adjustment of insulin dosage to meet individual requirements. Recent studies have shown significant improvement in reducing complications associated with Type 2 DM with controlled blood glucose levels. In these studies of over 5000 Type 2 DM patients, the risk of retinopathy and nephropathy was reduced by 25% with effective glycemic control, using sulfonyl ureas, metformin or insulin. The risk of developing hypoglycemia needs to be monitored in these patients on intensive treatment regimes, particularly those on insulin.
Oral and periodontal effects
Poorly-controlled diabetic subjects may complain of diminished salivary flow and burning mouth or tongue. Diabetic subjects on oral hypoglycemic agents may suffer from xerostomia, which could predispose to opportunistic infections with Candida albicans. Candidiasis has been reported in patients with poorly-controlled diabetes, associated with suppressed free oxygen radical release by PMNs and reduced phagocytosis.
There is good evidence to support the concept that there is an association between poorly-controlled diabetes mellitus and periodontitis.
Poorly-controlled Type 1 diabetes mellitus in a young female aged 19 years. (a) Very inflamed and swollen gingival tissues; early attachment loss was present. (b) The same patient after responding to a course of non-surgical periodontal treatment and improved oral hygiene.
Any differences in periodontal health between Type 1 DM and Type 2 DM patients may relate to differences in management of glycemic control, age, duration of disease, utilization of dental care, periodontal disease susceptibility and habits such as smoking. The Type 1 DM patients have an increased risk of developing periodontal disease with age, and with the severity and duration of their diabetes.
Periodontal attachment loss has been found to occur more frequently in moderate and poorly-controlled diabetic patients, of both Type 1 DM and Type 2 DM, than in those under good control. In addition, diabetics with more advanced systemic complications present with a greater frequency and severity of periodontal disease. Conversely, initial phase periodontal treatment comprising motivation and debridement of periodontal pockets in Type 2 diabetic patients resulted in improved metabolic control of diabetes. Insulin resistance can develop in response to chronic bacterial infection seen in periodontal disease, resulting in worse metabolic control in diabetic patients.
Probably the most classic description of the undiagnosed or poorly-controlled diabetic is the patient presenting with multiple periodontal abscesses, leading to rapid destruction of periodontal support.
A localized palatal periodontal abscess associated with a periodontal pocket in a 42-year-old poorly
controlled diabetic patient.
Radiographs of a 50-year-old male who developed Type 2 diabetes mellitus in the period between the two radiographs, which were taken 3 years apart. There has been rapid bone loss and tooth loss associated with recurrent multiple periodontal abscesses.Harrison et al. (1983) reported a case of deep neck infection of the submental, sublingual and submandibular spaces, secondary to periodontal abscesses involving the mandibular incisors, in a poorly-controlled diabetic patient. In a population study Ueta et al. (1993) demonstrated that diabetes mellitus was a predisposing factor for periodontal and periapical abscess formation due to suppression of neutrophil function. The effects on the host response, and in particular neutrophil function may account for this finding (Ueta et al. 1993).
Association of periodontal infection and diabetic control
The presence of acute infection can predispose to insulin resistance. This can occur independently of a diabetic state and persist for up to 3 weeks after resolution of the infection. In a longitudinal study of subjects with Type 2 DM, it was demonstrated that subjects with severe periodontal disease demonstrated significantly worse control of their diabetic condition than those with minimal periodontal involvement (Taylor et al. 1996).
Diabetes control and periodontal disease progression
Effect of diabetes mellitus on the host response
The incidence of proteinuria and cardiovascular complications, as a result of uncontrolled diabetes, was found to be significantly greater in diabetics with severe periodontal disease than those with gingivitis or early periodontal disease. Some studies have shown that stabilization of the periodontal condition with mechanical therapy, in combination with systemic tetracycline, improves the diabetic condition in such patients. Reduced insulin dosage in type 1 diabetics following periodontal treatment has also been reported.
Effects on healing and treatment response
Wound healing is impaired due to the cumulative effects on cellular functions , these factors include:
1. Decreased synthesis of collagen by fibroblasts
2. Increased degradation by collagenase
3. Glycosylation of existing collagen at wound mar-gins
4. Defective remodeling and rapid degradation of newly synthesized, poorly cross-linked collagen.
The treatment of well-controlled DM patients would be similar to that of non-diabetic patients for most routine dental procedures. The short-term nonsurgical treatment response of stable diabetics has been found to be similar to that of non-diabetic controls, with similar trends in improved probing depths, attachment gain and altered sub-gingival microbiota. Well-controlled diabetics with regular supportive therapy have been shown to maintain treatment results 5 years after a combination of non-surgical and surgical treatment. However, a less favorable treatment outcome may occur in long-term maintenance therapy of poorly-controlled diabetics, who may succumb to more rapid recurrence of initially deep pockets.
A Video on Effect of Diabetes on Periodontal Disease....
A Video on Effect of Diabetes on Periodontal Disease....