牙结石溶解物均相再沉积的初步研究

新鲜牙结石采用硝酸溶解成均相溶液,以模拟体液为对照组,采用均相沉积法形成钙磷复合物,场发射扫描电镜(FSEM)及傅立叶变换红外光谱(FT-IR)分析沉淀物的晶体形态和和结构,比较不同溶液反应体系及pH对晶体形态和结构的影响。结果表明:牙结石和对照组的均相溶液在pH=5.4时出现浑浊,5.6时出现沉淀,牙结石组在滴定至pH=5.4并陈化的条件下可形成叶片状晶体,形态与天然牙结石中的叶片状碳酰羟基磷灰石形态近似。牙结石组滴定至pH=5.6及对照组均不能形成叶片状晶体,FT-IR显示牙结石组为羟基磷灰石,对照组为磷酸八钙。以上提示天然牙结石溶解物采用均相沉积法实现体外重组可能与天然牙结石中存在模板分子有关。

Preliminary Study of Homogeneous Phase Redeposition of Dissolved Dental Subgingival Calculus

Fresh dental calculus were scratched and rinsed with distilled water, and then dissolved by HNO3. Simulated body fluid was used as control. Aqueous ammonia was added to step up the pH. FSEM and FI-IR were used to analyze the crystal character of deposition. Turbid occurred when pH=5.4 and deposition occurred when pH=5.6. Ribbon-like crystal, which was the same as the crystal in natural dental calculus was observed in experimental group and was evidenced to be hydroxyapatite (HAP) by FT-IR. HAP formation through homogeneous phase redeposition of dissolved dental subgingival calculus may be related with the existing template molecules in dental subgingival calculus resolution, which induce the biomineralization of HAP formation.