| Summary: | 碩士 === 中山醫學大學 === 口腔材料科學研究所 === 94 === Hydroxyapatite (HA) ceramics are currently used as bone graft substitutes because of its osteoconductivity. Silicon could enhance the bioactivity of materials. Zinc improves quantity and quality of osteoblast cells and acts as a stimulator on bone growth. We are to synthesize HA/Si via sol-gel route, followed by adding zinc oxide covering with chitosan to form a composite material.
The XRD patterns show that HA phases can be obtained at 500oC for pH 0 condition, but for pH 9 at lower temperature of 300oC. It can be seen the appearance of extra CaO and B-TCP phase. Concerning tensile strength, the value of monolithic HA derived from the sol-gel processing at pH 9 was much higher than that at pH 0, and higer pH value condition of sol could prevent diameter tensil strength decreased which was caused by silicon addition . There was no significant effect of ZnO addition on DTS value (p > 0.05) in the present study, however, enhancing an oriented growth of the HA phase on the (002) plane. The covering of chitosan didn’t effect the diameter tensile strength but bioactive, SEM microstructure shows more apatite formed on the chitosan surface after immersed in Hank’s solution for 30 days.
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