Dental implants in diabetic patients: retrospective cohort study reporting on implant survival and risk indicators for excessive marginal bone loss at 5 years.

More studies evaluating the outcome of dental implant restorations in diabetics are needed. To investigate the outcome of immediate function implant rehabilitations in diabetic patients. This retrospective cohort study included 70 diabetic patients (type 1 = six patients; type 2 = 64 patients; 33 females and 37 males, mean age=59 years), rehabilitated with 352 implants. Primary outcome measure was implant survival estimated at 5 years through the Kaplan-Meier product limit estimator using the patient as unit of analysis (first implant failure as reference); secondary outcome measures were marginal bone loss and biological complications. Risk indicators associated with bone loss >2·0 mm were tested in a multivariate logistic regression model. The level of significance considered was 5%. Seven patients were lost to follow-up (10%). Seven patients lost ten implants rendering a global implant cumulative survival rate for diabetic patients of 89·8% (type 1 = 80·0%; type 2 = 90·5%). The average (95% confidence interval) marginal bone loss at 1 and 5 years was 1·64 mm (0·00;3·32) and 2·55 mm (1·38;3·72) for type 1 diabetic patients, 0·79 mm (0·59;1·00) and 1·45 mm (1·09;1·82) for type 2 diabetic patients and 0·88 mm (0·65;1·10) and 1·56 mm (1·21;1·91) overall. Biological complications occurred in seven patients. Female gender (OR = 28·1) and smoking habits (OR = 10·3) were risk indicators for marginal bone loss >2·0 mm at 5 years when controlled for other variables of interest. Implant rehabilitations represent a valid treatment for diabetic patients, with a good risk/benefit ratio. Female gender and smoking habits were risk indicators for a higher marginal bone resorption at 5 years.