Effects of biphasic calcium phosphate on bone formation in human fetal osteoblasts

Abstract

The filling of bone defects resulting from trauma or periodontal disease requires bone grafts1). Autogenous bone grafts are some disadvatages related to this modality, especially lack of sufficient available bone and the need for a second intraoral or extraoral surgical site, which increases patient inconvenience and morbidity2). Therefore, there have led to the development of new synthetic or natural bone substitutes2). Bovine derived xenograft (BDX) is a natural bone substitute made from bovine bone via a proprietary extraction procedure. Osteoblasts form a layer on the BDX mesh and, osteoid and finally lamellar bone covers BDX trabecullae. BDX scaffold persists for some time which permits the correction of alveolar defects with permanent results 4). Biomaterials, such as calcium phosphate ceramics, appear to be suitable alternatives to bone grafts. Biphasic calcium phosphate(BCP) ceramics prepared from a close association of hydroxyapatite (HA) and β-tricalcium phosphate(β-TCP) were developed in the 1980s5). Calcium phosphate ceramics have been used mostly because of their close chemical and crystal resemblance to bone mineral. BCP is biocompatible and osteoconductive; it is able to promote new bone formation on contact, but it seems to have no intrinsic osteoinductive properties6). Macroporous type of BCP have been used for bone substitution for orthopedic surgery, and was carried out lots of experiments in vivo and in vitro for a long time5). Recently, The microstructure in the macropore surface enlarged greatly the surface area for protein adsorption, more proteins could be absorbed on the surface; the larger surface area could also facilitate ion exchanges and bone-like apatite surface formation by the process of dissolution and re-precipitation7). Therfore, the microand macro-porous BCP may be more favorable for bone ingrowth. But, microand macroporous BCP has not been studied sufficiently yet. The purpose of this study was to evaluate the potential of microand macro porous BCP compared with BDX to stimulate bone regener-