Mahmoud Mohseni - Department of Veterinary Surgery, Faculty of Specialized Veterinary Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Alireza Jahandideh - Department of Veterinary Surgery, Faculty of Specialized Veterinary Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Gholamreza Abedi - Department of Veterinary Surgery, Faculty of Specialized Veterinary Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Abolfazl Akbarzadeh - Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Saeed Hesaraki - Department of Pathobiology, Faculty of Specialized Veterinary Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran.

Objective- The loss of bone fragments, often due to trauma, infection, mass loss, or even complete bone regeneration after complicated fractures, is one of the constant challenges in medicine and veterinary medicine. The aim of this study was to fabricate and use a nanocomposite scaffold in segmental bone healing in rabbits.Design- Experimental StudyAnimals- Forty adult male New Zealand male rabbitsProcedures- The animals were randomly divided into four groups of ۱۰ animals each. On femur of each rabbit a bilateral ۶ mm diameter defect was created. In the first group (control), no substance was used, in the second group, hydroxyapatite, in the third group, nanocomposite tri-calcium phosphate (TCP) and in fourth group, autograft was used to fill the defect. Bone specimens were harvested for histopathological evaluations on days ۱۵ and ۶۰ for evaluation of four indices of union, spongiosa, cortex and bone marrow. Results- The results of using nanocomposite tricalcium phosphate in comparison with other groups were significantly different in all cases. Conclusion and Clinical Relevance- It could be admitted that nanocomposite tri-calcium phosphate scaffold had a positive effect on the healing process and showed satisfactory bone strength, therefore, it could be widely used in orthopedic surgery as well as tissue engineering.

Nanocomposite, tricalcium phosphate/collagen, histopathology, Bone healing, animal model