The reconstruction of large bone defects can not self-repair and needs bone grafts. It was aimed at investigating in vitro and in vivo biocompability of hydroxyapatite (HAp) based bioceramic materials that we produced.

In this study, 42 Spraq dawley rats were used for in vivo study. Rats divided into 3 groups equally. After general anesthesia, rats were drilled 2 defect of 2 mm on the upper poximal metaphysis of tibia. In the first group bone defect were left to heal by themselves without using any material. Bone defect were reconstructed with HAp material in the second group. Third group were filled with commercial HAp. Operation wounds were closed using routine surgery. The rats were sacrificed at the postoperative of 14^th or 28^th days. Histopathologicaly, It was observed that the HAp produced was in the ossicification process.

As a result, we need long term and more detailed examinations for evaluation of hydroxyapatite based bioceramic materials.