The use of 2 bioabsorbable barrier membranes in the treatment of interproximal intrabony periodontal defects

Background: The use of barrier membranes in the treatment of periodontal de fects is well documented. There has been an increase int he use of bioabsor bable materials which do not require a second surgical procedure for remova l. However, there are little data evaluating the efficacy of bioabsorbable membranes in the treatment of intrabony defects. The purpose of this invest igation was to evaluate the regenerative potential of 2 bioabsorbable barri er membranes without the use of grafting materials in the treatment of inte rdental intrabony defects. Methods: Twenty-three 2- or 3-walled intrabony defects were treated in 19 p atients with a mean age of 50.4 years. All had completed nonsurgical treatm ent and a period of supportive periodontal therapy. The sites were randomly chosen to receive a barrier membrane composed of type I bovine collagen (1 1) or a copolymer of polylactic acid (PGA/PLA; 12). A pressure sensitive di sc probe was used to evaluate the following criteria at baseline and re-ent ry: 1) occlusal surface to the apical depth of probe penetration (OS-DP); 2 ) occlusal surface to the gingival margin (OS-GM); 3) occlusal surface to t he alveolar crest (OS-AC); and 4) occlusal surface to the base of the osseo us defect (OS-BD). Full thickness mucoperiosteal flaps were reflected to ex pose the surgical sites. The defects were debrided of the granulomatous tis sue, the root surfaces instrumented and conditioned with 4 one-minute appli cations of 50 mg/ml of tetracycline. The barrier membranes were adapted to cover the defects and the flaps replaced. The postsurgical healing was unev entful and similar in both treatment modalities. Results: Twenty-three sites were surgically re-entered 6 months from the ti me of the initial surgery. The deepest probe depth for each site was used f or statistical analysis. There was a mean relative attachment gain of 2.58 +/- 1.90 mm for the collagen, and 2.77 +/- 2.13 mm for the copolymer. There was a decrease in probing depth of 3.27 +/- 1.91 mm and 0.69 +/- 1.35 mm o f recession for the collagen. The PGA/PLA copolymer had 3.55 +/- 2.47 mm re duction in probe depth and 0.78 +/- 1.14 mm of recession. Conclusions: The data indicated the bioabsorbable collagen and copolymer me mbranes resulted in comparable results. A larger sample size would be neces sary to determine if one membrane was superior to the other.