Enamel matrix proteins in the regenerative therapy of deep intrabony defects

Aim: This prospective multicentre randomized controlled clinical trial was designed to compare the clinical outcomes of papilla preservation flap surgery with or without the application of enamel matrix proteins (EMD). Material and methods: 172 patients with advanced chronic periodontitis were recruited in 12 centers in 7 countries. All patients had at least one intrabony defect of 3mm. Heavy smokers (20 cigarettes/day) were excluded. The surgical procedures included access for root instrumentation using either the simplified or the modified papilla preservation flap in order to obtain optimal tissue adaptation and primary closure. After debridement, roots were conditioned for 2 min with a gel containing 24% EDTA. EMD was applied in the test subjects, and omitted in the controls. Postsurgically, a strict plaque control protocol was followed. At baseline and 1 year following the interventions, clinical attachment levels (CAL), pocket probing depths (PPD), recession (REC), full‐mouth plaque scores and full‐mouth bleeding scores were assessed. A total of 166 patients were available for the 1‐year follow‐up. Results: At baseline, 86 test and 86 control patients presented with similar subject and defect characteristics. On average, the test defects gained 3.1±1.5 mm of CAL, while the control defects yielded a significantly lower CAL gain of 2.5±1.5 mm. Pocket reduction was also significantly higher in the test group (3.9±1.7 mm) when compared to the controls (3.3±1.7 mm). A multivariate analysis indicated that the treatment, the clinical centers, cigarette smoking, baseline PPD, and defect corticalisation significantly influenced CAL gains. A frequency distribution analysis of the studied outcomes indicated that EMD increased the predictability of clinically significant results (CAL gains 4 mm) and decreased the probability of obtaining negligible or no gains in CAL (CAL gains