Alveolar bone regeneration using poly-(lactic acid-co-glycolic acid-co-ε-caprolactone) porous membrane with collagen sponge containing basic fibroblast growth factor: an experimental study in the dog.

The aim of this study was to evaluate the effects of combining porous poly-lactic acid-co-glycolic acid-co-ε-caprolactone (PLGC) as a barrier membrane and collagen sponge containing basic fibroblast growth factor (bFGF) to promote bone regeneration in the canine mandible. In six beagle dogs, two lateral bone defects per side were created in the mandible. The lateral bone defects on the left side were treated with a PLGC membrane plus a collagen sponge containing bFGF. In half of these, the collagen sponge contained 50 µg of bFGF. In the other half, it contained 250 µg of bFGF. As a control, we treated the right-side bone defects in each animal with the same PLGC membrane but with a collagen sponge containing phosphate buffered saline. Computed tomography (CT) images were recorded at 3 and 6 months post-op to evaluate regeneration of the bone defects. After a healing period of 6 months, whole mandibles were removed for micro-CT and histological analyses. The post-op CT images showed that more bone had formed at all experimental sites than at control sites. At 3 months post-op, the volume of bone at defect sites covered with PLGC membrane plus 250 µg of bFGF was significantly greater than it was at defect sites covered with PLGC membrane plus 50 µg of bFGF. At 6 months post-op, however, this difference was smaller and not statistically significant. Micro-CT measurement showed that the volume of new bone regenerated at bone-defect sites, covered with PLGC membrane plus bFGF, was significantly greater than that of control sites. However, the presence or absence of bFGF in the collagen sponge did not significantly affect the bone density of new bone. These results suggest that the macroporous bioresorbable PLGC membrane plus collagen sponge containing bFGF effectively facilitates healing in GBR procedures.