Comparative Study of Micro Ostrich Eggshell and Hydroxyapatite onthe Healing of Bone Defect Created in the Rat Calvarium

BACKGROUND: Fracture healing is one of the important issues in medicine and veterinary. Therefore, finding new tech-niques with fewer side effects and faster healing is taken into consideration. OBJECTIVES: This study was conducted to evaluate the effect of the composites of micro ostrich eggshell (μ-OES) and hydroxyapatite (HA) composite on the healing of bone defect in rat calvarium. METHODS: Defects of 7 mm were made by a trephine in the calvaria of 45 male Wistar rats. The animals were divided into three groups and the defects in each group were filled with micro-composites that contained ostrich eggshell or HA or were left empty. The animals were euthanized at three different time points of 14, 28, and 42 days post-operation. Histological and serological assessments, such as measuring alkaline phosphatase were carried out at the same time points. RESULTS: Significant differences were observed in the granulation tissue formation of the treatment and control groups 14 days post-operation (P≤0.05). The difference between μ-OES and HA treatment groups was not statistically significant (P 0.05). On days 28 and 42, there were no significant differences between the groups. However, in the center of the defect, the mean of healing in the μ-OES group was higher than the two other groups. CONCLUSIONS: In conclusion, the results of this study indicated the potential efficacy of μ-OES as a bone substitute in a rat calvarial defect model.