Comparison of infrabony defects treated with enamel matrix derivative versus guided tissue regeneration with a nonresorbable membrane

AIM: The purpose of the present multicenter clinical trial was to compare the efficacy of two different procedures in the treatment of infrabony defects: guided tissue regeneration (GTR) with nonresorbable membranes and enamel matrix derivative (EMD). MATERIAL AND METHODS: Six centers participated in this study. Ninety-eight patients with an interproximal infrabony defect were selected. All patients were treated with an initial phase of scaling and root planing, and at the study's baseline the selected defects presented a value of probing depth (PD) > or =6 mm with an infrabony component > or =4 mm. Forty-nine patients were treated with GTR procedures (using ePTFE membranes (Gore-Tex W.L. Gore and Associates, Flagstaff, AZ, USA)) and forty-nine with EMDs (Emdogain (U Biora AB Malm, Sweden)). The efficacy of each treatment modality was investigated through covariance analysis. RESULTS: The patients were reevaluated at one year postop. Probing attachment level (PAL) gain and PD reduction were analyzed. In the Emdogain group the PAL before surgery (PAL 0) and the PD before surgery (PD 0) were respectively 9.9+/-1.4 and 8.5+/-1.6 mm. The PAL gain and the PD reduction at 1 year postsurgery were respectively 4.1+/-1.8 and 5.3+/-1.9 mm. The group of patients treated with membranes showed that PAL 0 and PD 0 were respectively 8.9+/-1.9 and 8.1+/-1.9. The PAL gain was 4.3+/-1.9 mm and the PD reduction was 5.6+/-1.5 mm. The mean PAL gain expressed by percentage (PAL gain/PAL 0) for the group treated with EMD was 41%, while it was 48% for the group treated with GTR. Results from our analysis suggest that there is no statistically significant difference between GTR and EMD treatments in terms of PAL gain, PD reduction and recession variation. Applying the regression model to a group of patients with a PAL 0 > or =8 mm, we observed a better clinical outcome in terms of PAL gain (difference of 0.3 mm) in patients treated with the GTR procedure compared to those treated with EMD. Covariance analysis showed a strong correlation in both groups of patients between PAL gain and full mouth bleeding score, and between PAL gain and defect morphology and depth