Evaluation of a biodegradable novel periosteal distractor.

摘要

We developed a new device composed of a thin biodegradable mesh (poly-L-lactide/hydroxyapatite composite) for distracting periosteum. The purpose of this study is to evaluate the effect of using this device as a periosteal distractor.Eight Japanese male rabbits were divided into two groups according to time of sacrifice. The calvarial periosteum was elevated and one side of a biodegradable mesh was fixed to the bone surface with two titanium screws. Seven days after the surgery, an elevating screw was inserted into the other side of the mesh. Then, the calvarial periosteum was elevated at maximum 0.5 mm every 12 h for 5 days. The device was designed to distract the periosteum at different rates along its entire surface. At 4 and 6 weeks of the consolidation, the animals were sacrificed and newly formed bone was histologically and radiographically evaluated.The new device simplified periosteal distraction and reduced its invasiveness. Moreover, it successfully induced new bone formation from two sources; the periosteum and the underlying basal bone. Histomorphometric analysis of the distracted space showed that there is a relation between the rate of distraction and the amount of newly formed bone. We suggest that the optimal speed range for periosteal distraction in rabbit calvarial model could be less than 0.33 mm/day.The new device is slim, biodegradable and the procedure is simple. Thus, periosteal distraction with this device is potential for vertical and horizontal ridge augmentation in oral cavity.