The safety and bone-regenerative capacity of a resorbable membrane (Resolut) was evaluated by a nonrandomized prospective clinical study of patients with periodontal defects. Prior to surgical management all patients underwent scaling and root planing and were instructed on oral hygiene. The study included 18 patients (31 periodontal defects) who received surgical treatment by guided tissue regeneration (GTR) using resorbable membranes. The results were evaluated 12 months after surgery in terms of Plaque Index, bleeding index, probing depth, gingival recession, clinical attachment level, and dental mobility. The results obtained show that the use of resorbable membranes in GTR causes few complications. The mean gain in clinical attachment level (4.06 ± 1.91 mm), with an attachment level gain of more than 3 mm in 81.2% of the defects, suggests the presence of 'new attachment.' This difference was clinically and statistically significant (t = 11.03, P = 0). The multivariate regression study showed that 60% of the observed variability (F = 11.48, P 0.001) in clinical attachment level gain was accounted for by the variable's initial probing depth, the Plaque Index of the tooth subjected to GTR, and the infrabony component of the defect.