The established correlation between diabetes and periodontal diseases and the increasing prevalence of Type II diabetes in the general population indicate that dental practitioners will probably treat an increasing number of diabetic patients. Despite the fact that there is little scientific evidence to support the concept, it has been generally accepted that treatment for periodontal disease in diabetic patients may reduce insulin requirements and improve metabolic balance. However, to date no one has evaluated the effects of periodontal therapy on the metabolic state of the poorly-controlled diabetic patient. The purpose of this pilot study was to evaluate the effect of controlling gingival inflammation on blood glucose levels as determined by glycosylation of hemoglobin and albumin.