Abstract
Bone defects might develop as a result of various pathological entities. Bone grafting is a widely used procedure that involves replacement of the missing tissue with natural or artificial substitute. The idea for artificial replacement of the missing bone tissue has been known for centuries and the evidence for these treatments has been found ever since prehistoric period. Bone grafting has been practiced for centuries with various non-osseous natural materials. The skeletal system plays a crucial role in the structural support, body movement and physical protection of the inner organs. Regeneration of bone defects is crucial for reestablishing of the form and function of the skeletal system,. While most bone defects can heal spontaneously under suitable conditions, bone grafts or substitute biomaterials are commonly used therapeutic strategies for reconstruction of large bone segments or moderate bone defect. An ideal bone grafting material should provide mechanical strength, be both osteoinductive and osteoconductive and should provide space for vascularization. In order to overcome limitations associated with the standard treatment of bone grafts, there is an increasing interest in studying substitute biomaterials, made of naturally derived or synthetic materials. Bone substitutes can be derived from biological products or from synthetic materials. Prior to testing in human subjects, the bone substitute materials should be tested in vitro and in vivo using animal models. Establishing of a suitable animal model is an essential step in the investigation and evaluation of the bone graft materials.