Use of barrier membranes and systemic antibiotics in the treatment of intraosseous defects

Objectives: Current literature is ambivalent on the use of barrier membranes for regeneration of intraosseous defects. One of the reasons for unpredictable results may be related to infection before, during and after the surgical procedure. Therefore, the purpose of the present controlled study was to evaluate both the use of membranes (MEM) and antibiotics (AB), separately and in combination. Methods: In all, 25 patients with two intraosseous periodontal defects each were randomized in two groups: AB+ group receiving systemic antibiotics (n=13) and AB-group without antibiotics (n=12). After raising flaps and after debridement, both defects in each patient were covered by a bioresorbable membrane (MEM+). However, just before suturing the flaps in a coronal position, the membrane over one of the two defects was removed at random (MEM-). This protocol resulted in four groups of defects: (i) MEM- AB-; (ii) MEM+ AB-; (iii) MEM- AB+; (iv) MEM+ AB+. Patients were monitored clinically and microbiologically for 1 year. Data were analyzed in repeated measures ANCOVA's and adjusted means for clinical variables were obtained from the final statistical model. Results: Reduction in probing pocket depth (PPD) at 12 months postoperatively varied between 2.54 and 3.06 mm between the four treatment modalities, but overall no main effect of MEM or AB was found. Gains in probing attachment level (PAL) at 12 months postoperatively varied between 0.56 and 1.96 mm for the 4 treatments. In the overall analysis for PAL, no main effect of MEM or AB was found. Gains in probing bone level (PBL) 12 months postoperatively ranged from 1.39 to 2.09 mm between the treatment groups. Again, overall, no main effects of MEM or AB were found for PBL. Explorative statistical analyses indicated that smoking and not MEM or AB is a determining factor for gain in PBL (P=0.0009). Nonsmokers were estimated to gain 2.04 mm PBL compared to 0.52 mm in smokers. The prevalence of several periodontal pathogens, at the day of surgery or postoperatively, and specific defect characteristics, were not determining factors for gain in PAL and PBL. Conclusions: Neither the application of barrier membranes nor the use of systemic antibiotics showed an additional effect over control on both soft and hard tissue measurements in the treatment of intraosseous defects. In contrast, smoking was a determining factor severely limiting gain in PBL in surgical procedures aimed at regeneration of intraosseous defects.