ABSTRACT
BACKGROUND: Chitosan exhibits good physiochemical properties and biocompatibility, but it has poor biological activity of osseointegration. Therefore, it needs to combine with other materials for bone repair. OBJECTIVE: Calcined bone/chitosan composite was prepared and its physiochemical properties and biocompatibility were analyzed. METHODS: Calcined bone/chitosan composite was prepared at a mass ratio of 1:2, 1:1, 2:1 respectively by solution blending method. The physicochemical properties of three composite materials were characterized. Passage 5 mouse L929 fibroblasts were treated with the leaching solution of three composite materials. The cytotoxicity of three composite materials was detected by the CCK-8 test. RESULTS AND CONCLUSION: (1) X-ray diffraction and Fourier Transform Infrared Spectroscopy showed that the essential components of three composite materials were hydroxyapatite and β-tricalcium phosphate. The characteristic diffraction peaks of hydroxyapatite/β-tricalcium phosphate increased with the increase of the proportion of calcined bone. (2) Scanning electron microscopy showed that calcined bone particles were evenly dispersed in chitosan medium. (3) With the increase of the proportion of calcined bone, the compressive strength of the composite decreased gradually. (4) After 7 days of culture, the cells in the leaching solution of three composite materials grew well without obvious change in morphology. By the ninth day, the relative proliferation rate of the cells in the leaching solution of three composite materials was over 90%. Cytotoxicity was grade 1, which meets the safety standard of biomaterials. (5) These results suggest that the calcined bone/chitosan composite has good structural characteristics, physicochemical properties and suitable compressive strength and is safe and non-toxic.
ABSTRACT
Objective:To study the efficacy and safety of natural calcined bone repair material(NCBM)in repairing bone defect af-ter tooth extraction.Methods:A randemized,double-blinded,parallel,positive control(Bio-Oss)and multi-center clinical trial was employed.Imaging examination was used as the main efficacy evaluation index,surgical wound healing,rejection reaction,bone me-tabolic changes,bone infection signs were the subordinate efficacy evaluation indexes,the incidence of adverse reactions was observed for safety evaluation.Results:280 cases were included,269 cases completed the trial.In NCBMand Bio-Oss group the effective rate of imaging examination was 93.08% and 93.70%(P >0.05)respectively.The wound healing time of the 2 groups was less than 7 days,no rejection reaction,bone metabolic change and bone infection sign were observed.The incidence of adverse events in NCBM and the Bio-Oss group was 0.72% and 2.14%(P >0.05)respectively.Conclusion:The efficacy and safety between natural cal-cined bone repair material is not inferior to Bio-Oss in repairing bone defect after tooth extraction.