The primary purpose of this study will be to determine whether an overlay mandibular denture supported by osseointegrated dental implants is an effective treatment alternative to a conventional complete denture in diabetic patients whose metabolic biochemical control is achieved primarily either by dietary therapy, which may be supplemented by oral hypoglycemic agents, or by insulin. The effectiveness of the two types of dentures would be based upon improvements in denture comfort, masticatory efficiency, food selection, dietary intake, quality of life, patient satisfaction and cost of initial and maintenance care. One hundred and eight elderly male diabetic patients with acceptable metabolic control will be randomly assigned to four groups providing two control groups, one with 24 insulin treated (IT) and the other with 24 non-insulin treated (NIT) patients and two experimental groups, one with 30 IT and the other with 30 NIT patients. Patients in the control groups will receive a new set of maxillary and mandibular dentures and in the experimental groups a new maxillary denture and an overlay mandibular denture supported by two osseointegrated implants. They will be followed in the Diabetic Clinic on a quarterly basis for glycosylated hemoglobin concentrations and in the Dental Clinic for observation and oral hygiene instructions. In addition, they will be instructed to monitor their fasting glucose levels at least three times a week. A series of clinical evaluations and subjective and objective measurements will be made immediately after entry into the study and at 6-month and 36-month intervals after the insertion of new dentures. Three sets of questionnaires (food preference, patient treatment evaluation and patient satisfaction) will be administered to determine perceived changes in mastication, speech, odor, denture hygiene, comfort, security and psychological well-being. The objective measurements will include salivary secretion rates, tactile discrimination thresholds, maximal biting pressures, oral clearance tests, and masticatory performance tests, electromyographic activity and mandibular movement recordings. A one-week dietary log will be kept to determine changes in food consumption patterns in terms of the degree of difficulty to chew foods. Comparisons between the two treatment groups will be made on the differences in percentages of treatment failures based on prespecified criteria as well as differences in the mean scores for each of the subjective and objective variables.
