An in vitro evaluation of the antibacterial properties of barriers used in guided tissue regeneration.

The inhibition of growth of Prevotella nigrescens and Enterococcus faecalis by three barriers membrane, (a) polylactic acid (Atrisorb), (b) laminar bone, and (c) calcium sulfate, was compared using an agar diffusion test. The first group of 20 plates were inoculated with P. nigrescens in a prereduced anaerobically-sterilized brain-heart infusion broth, while the second group of 20 plates were inoculated with E. faecalis in a brain-heart infusion broth. On each plate, a 5.0-mm section of each barrier was placed such that every plate had all three barriers. The plates in the P. nigrescens group were incubated in an anaerobic chamber for 7 days. The plates in the E. faecalis group were incubated at 37 degrees C for 2 days. No zones of inhibition were observed with laminar bone or calcium sulfate. Zones of inhibition were observed with the Atrisorb barrier membrane in both groups. The zone of inhibition of P. nigrescens was significantly greater than the zone of inhibition of E. faecalis. The hydrophobicity of Atrisorb and its N-methyl-2-pyrolidine component were suggested as the sources of its antibacterial activity.