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Development of hard tissue inductive calcium phosphate root canal filling materials containing mucopolysaccharide

含粘多糖硬组织诱导磷酸钙根管充填材料的研制

基本信息

批准号：
13672016
负责人：
TODA Tadao
金额：
$ 2.11万
依托单位：
Osaka Dental University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

An equimolar mixture of tetracalcium phosphate and dibasic calcium phosphate-2 hydrate were selected for the solid phase of bio-active cement. The mixture has buffer action of the solid phase. This mixture is kneaded with buffer solution including low concentration of citric acid. Sodium chondroitin sulfate was included in this liquid phase. In hardening process, the pH value of this cement showed 8.4-8.5. The pH value of neutral region might suggest biocompatibility of this cement.The result of in vivo experiment showed that the cement cause no inflammatory reaction. This cement including chondroitin sulfate might promoted the hard tissue formation. Hard tissue was added in root canal wall just under the cement applied on the amputated pulp surface. The root canals were ultimately closed. The cement was experimentally extruded in periapical tissue via the apical foramen. The cement in defected alveolar bone was absorbed immediately. Reconstruction of alveolar bone with absorption of cement was recognized.In this study, calcium phosphate cement was kneaded in low concentration of citric acid solution. In hardening reaction of low concentration of citric acid solution and calcium phosphate particles, calcium phosphate particles coagulate mutually. Hydroxyapatite constructing the hardened cement shows low crystallinity. In vivo experiment in subcutis, macrophages and multinucleated giant cells were observed around the cement in setting process. These cell should accumulated to phagocytose calcium phosphate fine particles.It was considered that improvement required in setting time and/or hardening reaction of the cement. On the other hand, it is a fact that this cement is bioresorvable material because of the low crystallinity. It is considered that this cement is effective for bone reconstruction.

生物活性水泥的固相采用磷酸四钙和水合磷酸二钙等摩尔比的混合物。混合物具有固相的缓冲作用。这种混合物用含有低浓度柠檬酸的缓冲溶液捏合。该液相中含有硫酸软骨素钠。在硬化过程中，该水泥的pH值为8.4~8.5。中性区的pH值表明该骨水泥具有良好的生物相容性，体内实验结果表明该骨水泥不会引起炎症反应。含硫酸软骨素的骨水泥可能促进了硬组织的形成。将硬组织加入到根管壁中，紧贴在断髓表面的粘固剂下面。根管最终关闭。通过根尖孔在根尖周组织中试验性地挤出粘固剂。缺损牙槽骨中的骨水泥即刻吸收。在本研究中，磷酸钙骨水泥是在低浓度柠檬酸溶液中捏合而成。在低浓度柠檬酸溶液与磷酸钙颗粒的硬化反应中，磷酸钙颗粒相互凝聚。羟基磷灰石构成的硬化水泥结晶度低。体内实验观察骨水泥固化过程中的皮下组织、巨噬细胞和多核巨细胞。这些细胞堆积成吞噬状的磷酸钙微粒。认为需要改善水泥的凝结时间和/或硬化反应。另一方面，由于结晶度低，这种水泥是可生物再利用的材料。认为该骨水泥是一种有效的骨重建材料。