Guided bone regeneration using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-cross-linked type-I collagen membrane with biphasic calcium phosphate at rabbit calvarial defects

BACKGROUND In-vitro and animal studies using EDC cross-linked membranes have shown great resistance to enzymatic digestion as well as low cytotoxicity, and indicated its potential expediency as a barrier membrane for guided bone regeneration (GBR). The purpose of this study was to evaluate the efficacy, biocompatibility and degradation kinetics of a novel 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-cross-linked type I collagen membrane for regeneration of rabbit calvarial defects. EDC cross-linked type I collagen membrane and macroporous biphasic calcium phosphate (MBCP) consisting of 60 % hydroxyapatite and 40 % β-tricalcium phosphate were used in this study. Four circular defects (ø = 8 mm) were created in each calvarium of 12 male white rabbits. The experimental groups randomly allocated to the defects were as follows - (1) sham control, (2) EDC-cross-linked collagen membrane (EDC membrane), (3) bone graft (BG), and (4) bone graft with collagen membrane (B-EDC membrane). Specimens were harvested at 2 weeks (n = 6) and 8 weeks (n = 6) postoperatively for observational histology and histometrical analysis. RESULT The histologic observation showed close adaptation of the EDC membrane to the defect perimeters along with vascularization of the membrane at 2 weeks. Direct apposition of new bone on to the collagen matrix could be observed displaying adequate tissue integration. Collapsing of the central portion of the membrane could be seen in the EDC membrane group, and both BG and B-EDC membrane groups showed greater total augmented area and new bone area than the EDC membrane group. The membrane was largely unresorbed at 2 weeks; and at 8 weeks the overall shape of the membrane was still maintained suggesting sustained barrier function at 8 weeks. CONCLUSION Within the limits of this study, it may be concluded that EDC-cross-linked collagen membrane is a safe biomaterial with adequate tissue integration and resorption kinetics to support bone regeneration when used in conjunction with bone filler.