Repair of maxillary alveolar cleft defects with two different bioabsorbable implants: an experimental study in growing rabbits

Abstract

Two different bioabsorbable implants and their ability to promote bone formation in repair of experimental maxillary defects were investigated. A poly-L/D-lactide mesh and a two-layer composite membrane consisting of a film made of a copolymer of L-lactic acid and e-caprolactone combined with the polylactide mesh were used as implants. A standard alveolar defect was made bilaterally in the maxilla and filled with autogenous bone grafts in 30 growing rabbits. Follow-up was 10 weeks. Three experimental groups were formed: (1) defect covered with polylactide mesh versus control defect without implant, (2) defect covered with composite membrane versus control defect, and (3) defect covered with membrane on one side and with mesh on the other. Radiological, histological and histomorphometric evaluations were performed. In histomorphometric measurements, a significantly larger quantity of bone was observed in the composite membrane-covered defects compared with the polylactide mesh-covered and the control defects. Osteogenic activity was also highest in the membrane-covered defects. The bioabsorbable composite membrane appears to promote healing of experimental maxillary alveolar defects in accordance with the principle of guided tissue regeneration. The polylactide mesh alone was less potent in promoting healing of the defect, although an enhancing effect on osteogenic activity was observed.