Healing following GTR treatment of intrabony defects distal to mandibular 2nd molars using resorbable and non-resorbable barriers

Aims: The objectives of the present, randomised clinical trial were (i) to evaluate the healing of periodontal intrabony defects at the distal aspect of mandibular 2nd molars using a resorbable polylactic acid (PLA) barrier and a non-resorbable polytetrafluoroethylene (e-PTFE) barrier and (ii) to compare the therapeutic effect of the bioresorbable versus the non-resorbable barrier. Method: 19 patients with intrabony defects distal to mandibular 2nd molars greater than or equal to 4 mm (on radiographs) were included in the study. The defects all remained 5 years after surgical removal of impacted 3rd molars. Following flap elevation and defect debridement, the defects were randomly covered with, either a resorbable PLA or a non-resorbable e-PTFE barrier. Flaps were repositioned and sutured to completely cover the barriers. Treatment was evaluated clinically after 1 year by measurements of probing depth (PD), probing attachment level (PAL), and probing bone level (PBL) and radiographically by measurements of bone levels on computer digitised images of radiographs taken immediately before and 1 year postsurgery. Results: Both treatments resulted in significant PD reduction, PAL gain, and bone fill. The total PD reduction was 5.3+/-1.9 mm for the PLA treated sites and 3.7+/-1.7 rum for the e-PTFE treated sites (p<0.05). The corresponding values for PAL gain were 4.7+/-0.7 mm and 3.6+/-1.7 mm (p<0.05) and for PBL gain 5.1+/-1.2 and 3.3+/-2.0 mm (p<0.05). Radiographic bone fill averaged 3.4+/-1.2 for the PLA and 2.0+/-1.6 mm for the e-PTFE barriers (p<0.05). Radiographic bone level measurements were significantly smaller than the corresponding clinical measurements, indicating that radiographs tend to underestimate bone fill. Conclusions: GTR treatment of deep intrabony defects distal to mandibular second molars using resorbable PLA barriers resulted in significant PD reduction, PAL gain and bone fill at least equivalent to the results obtained using nonresorbable e-PTFE barriers.