低水解型聚胺酯及雙凝聚合胺酯壓克力在牙科根管填充材料之應用

Abstract

本研究主要利用聚胺酯以及胺酯壓克力樹酯以研發牙科根管填充材料。實驗將分為根管填充材以及封填劑兩部份。根管填充材部分主要是利用聚胺酯做為材料基質，並使用氧化鋅做為填充料，開發應用於牙科根管填充針之氧化鋅及聚胺酯複合材料。結果顯示以聚碳酸酯型聚胺酯做為基材之氧化鋅聚胺酯複合材料在牙科根管填充材有相當大的發展潛力。機械性質方面，聚碳酸酯型聚胺酯做為基材之氧化鋅聚胺酯複合材料已高於臨床上常用的牙科根管填充材；熱性質方面聚胺酯相較於臨床材料之熔點，聚碳酸酯型聚胺酯的熔點較低；在水解性質測試上，聚碳酸酯型聚胺酯則表現出明顯的耐水解特性，其重量損失百分比相較於聚酯型聚碳酸酯為低。因此在根管填充針方面，聚碳酸酯型聚胺酯做為基材之氧化鋅聚胺酯複合材料於根管治療臨床應用尚有不少發展空間。 牙科根管填充封填劑，本部份利用可見光可硬化之胺酯壓克力樹酯做為基質，並使用三丙烯乙二醇雙丙烯酸酯做為稀釋單體提高胺酯壓克力樹酯於牙科根管封填劑上之可行性。結果顯示，以二異氰酸異佛爾酮作為異氰酸鹽之胺酯壓克力樹酯以七比三之重量比例和三丙烯乙二醇雙丙烯酸酯之混合樹酯黏度最適當，並以樟腦醌及對二甲胺基苯甲酸乙酯之混合作為本系統樹酯之光起始劑，並添加偶氮二異丁腈做為熱起始劑，以雙凝聚合的方式使得硬化能更加完全。操作性方面，胺酯壓克力材料之流動性質已通過國際標準認證第六八七六號封填劑部分之最低標準。硬化深度測試上，相較於臨床使用之牙根管填充材，胺酯壓克力也有足夠的硬化深度。結果也指出，以胺酯壓克力和氧化鋅聚胺酯複合材料作為牙科根管填充封填劑和針，和牙齒的黏合度也較一般臨床使用之材料高。因此在根管填充封填劑方面，推測胺酯壓克力未來於根管治療臨床應用上之潛力極高。

The purpose of this study was to develop a novel polymer-based root canal obturation material. Thermal polyurethane (TPU) was synthesized from polycarbonate-type polyol, and zinc oxide (ZnO) was added into TPU as filler to form the ZnO/TPU composite. Results showed that polycarbonate-type polyurethane and zinc oxide composite materials have great potential in root canal filling materials. In mechanical properties, it is shown that tensile strength and modulus of the ZnO/TPU composites can both be higher than gutta-percha and Resilon. For thermal properties, ZnO/TPU composite has lower melting than gutta-percha and Resilon. For hydrolysis test, polycarbonate-type polyurethane shows obvious properties of low-hydrolysis, explained by lower weight loss percentage than polyester-type polyurethane. Thus, it is found that ZnO/TPU composite still requires further investigations for clinical applications. For the sealer resin part, visible-light photopolimerizable urethane-acrylate oligomer was synthesized and mixed with dilute monomer to form UA/TPGDA resin. The relative molecule weight, viscosities, bonding strength, interface between sealer and dentin were investigated in this research. Results indicate that the viscosity of UA/TPGDA resin can be altered by the TPGDA content. The photo-initiator for UA/TPGDA (7/3 by wt.) is the mixture of camphorquinone and ethyl 4-dimethylaminobenzoate (1/2 by wt.) with concentration 3 phr, and it includes AIBN, also with concentration 3 phr, which is used as a thermal-initiator. We anticipated that the dual-curing method will improve the curing depth of the present system, and results show that the curing depth is satisfactory for clinical application. In flow analysis test , urethane-acrylate has passed the lowest acceptable standard of ISO 6876. As for bonding strength, results show that bonding strength of the UA/TPGDA (7/3 by wt.) and polyester-type polyurethane which were used as sealer and cone is the highest of all other groups of sealer and cone. It is found that visible-light curable urethane-acrylate oligomer has great potential in the root canal filling material sealer.