Nano-hydroxyapatite for repair of rabbit jaw bone defect Bone mineral density analysis / 中国组织工程研究

ABSTRACT

BACKGROUND: Nano-hydroxyapatite (Nano-HA) has been shown to be a good choice of bone repair material owing to its salts composition consistent with natural bone and its scaffold structure homothetic to natural bone structure. OBJECTIVE: To investigate the feasibility of nano-HA in repair of jaw bone defect in rabbits. DESIGN, TIME AND SETTING: Materials-based animal experimental observation was performed at Laboratory Animal Center of Jiamusi University and Beijing Ji Shui Tan Hospital between January 2003 and June 2005. MATERIALS: Neutralization reaction of calcium biphosphate and calcium hydroxide was used to construct the system. The reactants were managed to be cotloidal by reaction control and using appropriate nucleating agents. Acerata HA crystal obtained under different conditions was sintered to obtain the nano-HA granule with a diameter of 1-56 nm. METHODS: Twenty-four healthy Chinese Harbin rabbits were randomly and evenly divided into an experimental group and a control group. After anesthesia, a penetrating 1.5 cm x1.5 cm defect was made with the GX micro-drill at the mandibular edge in each rabbit. Nano-HA was implanted in defects of the experimental group, and common HA was used in the control group. Antibiotics were used for 5 days afterwards. MAIN OUTCOME MEASURES: Change in bone mineral density after implantation of nano-HA. RESULTS: After repair of bone defect, the bone mineral density in the expedmental group increased gradually to a normal level and tended to be stable; whereas it was gradually decreased in the control group. There was significant difference between the experimental and control groups (P < 0.01). CONCLUSION: Nano-HA can promote new bone maturation, and this material produces favorable results in repair of bone defects.