Abstract

Diabetes mellitus has been linked with an increased risk for oral diseases, especially periodontal diseases (Oliver & Tervonen 1994, Yalda et al. 1994). Further investigations have, however, shown that this risk is not equal in all patients with diabetes. These studies explored the relationship between the diabetic status and periodontal diseases, dental caries and salivary factors. In a group of the diabetic adolescents aged 12 to 18 years, dental caries and gingivitis were shown to associate with poor metabolic control of diabetes. An increase of caries prevalence and the severity of gingivitis was evident in alarmingly poorly controlled patients with glycosylated haemoglobin (HbA₁) values of 13% or higher. The hyperglycaemia-associated increase of gingivitis was confirmed in a group of newly diagnosed diabetic children and adolescents, whose gingival inflammation decreased during a follow-up after the correction of hyperglycaemia by initiation of insulin treatment. Decreased salivary flow rates and elevated salivary glucose levels were observed during the hyperglycaemic state of children and adolescents with newly diagnosed diabetes. Higher salivary microbial counts, especially yeast counts, were related to the lower salivary flow rates and higher salivary glucose levels.

In adult patients with type 1 diabetes, the complex diabetic status was assessed by means of the level of metabolic control and/or the presence and severity of diabetic complications. Adult diabetic patients with poor metabolic control and/or complications exhibited more deepened pockets and clinical attachment loss, and after periodontal treatment, the recurrence of deepened pockets was faster in these patients compared to the other diabetic patients or the controls. The high-risk subjects among adults with type 1 diabetes were categorised as follows: subjects with long-term HbA₁ values over 10%, independently of whether the patient has diabetic complications or not; subjects with advanced diabetic complications, such as preproliferative or proliferative retinopathy, nephropathy, limb amputations or recurrent infections; and subjects with multiple diabetic complications, irrespective of the level of metabolic control.

In conclusion, dental professionals should be aware of the level of glycaemic control in their patients with type 1 diabetes, and the prevention and intensified treatment should be focused on those with a poor metabolic control (HbA_1c values around or over 10%). In the case of adult patients, more comprehensive knowledge about the diabetic status of the patients is needed in order to be able to identify the subjects at high risk for periodontitis and in need of regular maintenance care at least twice a year. The medical and nursing personnel should also be aware of periodontitis as a complication of diabetes, and especially in the case of adult diabetic patients, they should refer their patients to dental treatment when necessary.