Moldable β-TCP Bone Grafting System in Rabbit Condyle Critical-Sized Defect
Objectives: Stabilization of bone graft in a defect is an important condition for successful bone formation. The new β-TCP Bone Grafting System (GUIDOR® easy-graft® CLASSIC) was designed to be a moldable bone graft that hardens into a stable, porous scaffold upon contact with body fluids. The aim of this study was to evaluate new bone formation with or without a bioresorbable membrane (GUIDOR® Bioresorbable Matrix Barrier) in a rabbit critical-sized condyle defect, simulating an extraction socket.
Methods: A single defect (5 mm x 10 mm) was created in the lateral condyle of each femur. Each defect was filled with either the test article alone (T1) or test article plus bioresorbable membrane (T2) or remained untreated (sham). The defect site was closed by 4-0 absorbable suture. At 6 and 12 weeks, the designated animals (10 at 6 weeks, 12 at 12 weeks) were euthanized and the histological specimens (defect sites) were prepared for the following microscopic assessments: osteointegration/bone apposition scores, new tissue/bone ingrowth and local tissue response. At each interval, the responses to each treatment were compared to one another and to the sham.
Results: T1 and T2 exhibited local irritation at 6 and 12 weeks compared with the sham, however no difference in local irritation was observed between T1 and T2. Bone formation scores were similar for T1 and T2 and both were greater than the sham. The implanted bone graft was well stabilized in both T1 and T2. The barrier structure was observed in T1 at 6 weeks but not at 12 weeks. The granules of bone graft became fragmented at 6 and12 weeks in T1 and T2.
Conclusions: The study demonstrated that easy-graft system facilitated new bone formation at an equivalent level with or without a bioresorbable membrane in the critical-sized bone defect.