EFFECT OF POLYGLYCOLIC ACID MEMBRANE ON BONE REGENERATION AROUND TITANIUM IMPLANTS INSERTED IN BONE SOCKETS

An experimental animal model was used to evaluate the value of resorba ble, non-permeable polyglycolic acid (PGA) membranes in relation to fi xtures implanted into simulated extraction sockets. Branemark fixtures (length 7.0 mm, diameter 3.75 mm) were implanted into edentulous area s of maxillary bone in six sheep. Five fixtures were covered with 0.15 -mm-thick PGA membrane (Biofix(R)) held in place with a cover screw (P GA group) and five were implanted without membrane (control group). Th e animals were killed after 4 months and undecalcified mesiodistal sec tions were prepared from resected jaw specimens. Histomorphometry was used to measure the distance from the shoulder of the fixture to the l evel of intimate bone contact (SB distance). SB distance was found to be greater in the PGA than in the control group in relation both to th e mesial (1.44 +/- 0.88 mm versus 0.96 +/- 0.47 mm) and distal (1.13 /- 0.80 mm versus 0.77 +/- 0.63 mm) aspects of implants. This statisti cally not significant difference in bone regeneration between the two groups is related to the physical properties of the PGA membrane used.