Design features of the Diabetes and Periodontal Therapy Trial (DPTT): A multicenter randomized single-masked clinical trial testing the effect of nonsurgical periodontal therapy on glycosylated hemoglobin (HbA1c) levels in subjects with type 2 diabetes and chronic periodontitis

Abstract Background Evidence suggests that periodontitis is associated with prevalent and incident type 2 diabetes mellitus (T2DM), raising the question of whether periodontitis treatment may improve glycemic control in patients with T2DM. Meta-analyses of mostly small clinical trials suggest that periodontitis treatment results in a modest reduction in glycosylated hemoglobin (Hb) A1c. Purpose The purpose of the Diabetes and Periodontal Therapy Trial (DPTT) was to determine if periodontal treatment reduces HbA1c in patients with T2DM and periodontitis. Methods DPTT was a phase-III, single-masked, multi-center, randomized trial with a planned enrollment of 600 participants. Participants were randomly assigned to receive periodontal treatment immediately (Treatment Group) or after 6 months (Control Group). HbA1c values and clinical periodontal measures were determined at baseline and 3 and 6 months following randomization. Medication usage and dosing were assessed at each visit. Periodontal treatment consisted of scaling and root planing for a minimum of two 90-minute sessions, plus the use of an antibacterial mouth rinse for at least 32 days afterwards. The primary outcome was change in HbA1c from baseline to 6 months and the trial was powered to detect a between-group difference of 0.6%. Secondary outcomes included changes in periodontal clinical measures, fasting plasma glucose, the Homeostasis Model Assessment (HOMA2) and the need for rescue diabetes or periodontal therapy. Conclusion Dental and medical researchers collaborated to recruit, treat and monitor participants with two chronic diseases to determine if treatment of one condition affects the status of the other.