The influence of three barrier membranes on modeling and incorporation of autologous onlay bone grafts in rats. An evaluation by transversal microradiography.

Objectives: To determine whether covering an autologous bone grafts with three different barrier membranes prevents graft resorption, and to compare these membranes to each other.

Design: In 192 rats a standardised 4.0mm diameter bone graft was harvested from the right mandibular angle and transplanted to the left. Membranes used to cover the grafts were a new poly(DL-lactide-epsilon-caprolactone) membrane, a collagen and expanded polytetrafluoroethylene membrane. The controls were left uncovered. Graft resorption and incorporation were measured with transversal microradiography (TMR) in the four groups at 2, 4 and 12 weeks. Data were analysed using multiple regression analyses.

Results: Overall, there were no differences in modeling with resorption between the four groups. ePTFE at 12 weeks showed a lower mineralization ratio and graft height of the graft as compared to the other groups. The mean graft incorporation was progressive and nearly identical from 2 to 12 weeks in all groups.

Conclusions: Membranes have an equal effect on bone graft modeling and resorption as found in non-covered controls. Therefore, the indication to use a barrier membrane to prevent bone modeling with resorption and enhance incorporation of autologous onlay bone grafts is disputable.