Evaluation of a poly-l-lactic acid membrane and membrane fixing pin for guided tissue regeneration on bone defects in dogs

Objectives. The purpose of the study was to clarify the usefulness of a poly-l-lactic acid and membrane fixing pin, used in combination with guided bone regeneration, on bone defects in dogs. Study design. Osteotomies bone defects were created in 8 beagle dogs. Group I: one defect was covered with test membrane and held by fixing pins. Group II: the other defect was covered test membrane and not held by fixing pins. The control group received no membrane. The dogs were killed after 24 or 36 weeks of healing. Sections were stained and evaluated microscopically. Data were analyzed statistically. Results. The degradation and resorption of test membrane was not observed at 24 weeks but was noted at 36 weeks. After 24 and 36 weeks, most of Group I defects were completely closed with new bone, while in the control defects, only a small amount of new bone was observed at the bottom of the bone defects. After 36 weeks, the percentage of new bone volume (62.2%) in the space beneath the test membrane and membrane fixing pin (Group I) was greater than that without a membrane fixing pin-53.2% (Group II), whereas only 43.9% of the defect area in the control group was filled with new bone. Conclusion. The results of this study show that a poly-l-lactic acid membrane and membrane fixing pin permit bone regeneration that can be ensured by excluding surrounding soft tissues from the wound area.