RÉSUMÉ
Autograft is the best bone graft substitute, however, it has some limitations, so allograft with synthetic or natural materials has been advised to use for bone graft. In this study, Iranian Caspian seashell was used as a biocompatible natural material for radiological evaluation. Lodgment of seashell in drilled defects of femur was compared in the treatment group [rabbit models] with natural healing process of cancelluos bone in the control group. Handling characteristics, osteoconductivity, resisting against bone forces and absorption, were evaluated by radiological study. The study was performed in faculty of Veterinary Medicine, Islamic Azad University of Karaj. Twelve New Zealand rabbits were divided into two equal groups of six [treatment and control groups]. In the treatment group unilateral drilled defect was induced in the greater trochanter of femur. Each defect was implanted by the pieces of seashell. In the control group, similar bone defects was also produced to study natural bone healing process. Radiographs were taken from rabbits in 0, 10, 20, 30, 40, 50, 63 days post-operation. After 9 weeks, radiographic findings in the treatment group were included; a range of 10-15% reduction of bone density and progressive new bone formation in the presented bone defects. Results of radiographic evaluation in the control group, indicated more than 50% of bone healing was developed in the cylindrical defects of femoral greater trochanter. [...] Due to high structural density of seashell, which makes it tolerable against local biomechanical bone stress, there was no post-surgical complication [such as trochanteric fracture] in the treatment group. Seashell is a natural source of calcium which is a valuable substitute for bone grafts in medical and veterinary orthopedic surgeries