聚胺酯及胺酯壓克力樹脂於牙科根管填充材料上之應用

Abstract

中文摘要 本研究主要利用聚胺酯以及胺酯壓克力樹脂以研發牙科根管填充材料。實驗將分為根管填充針以及封填劑兩部份。根管填充針部分主要是利用聚胺酯做為基材，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。結果顯示不論機械性質或熱性質方面，聚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針之應用上極具潛力。機械性質方面，聚酯型聚胺酯做為基材之氧化鋅聚胺酯複合材料已超越臨床上常用的牙科根管填充針；熱性質方面也具有相似於臨床材料之熔點以及較低的比熱和熔化熱。因此在根管填充針方面，聚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上之可能性極高。 牙科根管填充封填劑，本部份利用可見光硬化之胺酯壓克力樹脂做為基材，並使用三丙烯乙二醇雙丙烯酸酯做為稀釋單體，提高胺酯壓克力樹脂於牙科根管封填劑上之可行性，另外還使用經甲基丙烯酸羥基乙酯修飾之奈米二氧化矽做為填充料，兩者搭配使用形成胺酯壓克力及二氧化矽奈米混成材料。結果顯示，使用二異氰酸異佛爾酮之胺酯壓克力樹脂以七比三之重量比例和三丙烯乙二醇雙丙烯酸酯混合之樹脂黏度最適當，並以camphorequinone與對二甲胺基苯甲酸乙酯之混合最適合作為本系統樹脂之光起始劑，而百分之三重量百分濃度為最適當之起始劑濃度會使硬化後之樹脂具有最高的機械性質。此外，本實驗研發之胺酯壓克力及二氧化矽奈米混成材料在聚合後體積收縮量極小，純胺酯壓克力樹脂甚至在聚合後還有些微膨脹。操作性方面，胺酯壓克力樹脂及二氧化矽奈米混成材料之流動性質已通過ISO-6876流動性之最低標準。結果也指出，以胺酯壓克力樹脂及二氧化矽奈米混成材料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。由掃描式電子顯微鏡對於胺酯壓克力及二氧化矽奈米混成材料和齒壁黏合情形做分析，發現胺酯壓克力及二氧化矽奈米混成材料可以流入牙根管壁上的牙小管並在其中硬化。最後洛華盛的混攙使胺酯壓克力混成材料在硬化後具有抗菌性。因此在根管填充封填劑方面，胺酯壓克力與二氧化矽奈米混成材料未來於臨床治療上之可能性極高。

The purpose of this study was to develop a novel polymer-based root canal obturation material. Thermal polyurethane (TPU) was synthesized from polyester-type polyol, and zinc oxide (ZnO) was added into TPU as filler to form the ZnO/TPU composite. The mechanical properties, thermal properties and specific heat of the ZnO/TPU composite were investigated and compared to gutta-percha and Resilon in this research. Results showed that tensile strength and modulus of the ZnO/TPU composites can both be higher than gutta-percha and Resilon. Enthalpy change of the ZnO/TPU composite during phase transition is near gutta-percha but is lower than Resilon. There is no significant difference in melting point among ZnO/TPU composite, gutta-percha and Resilon. Specific heat of the ZnO/TPU composite is near gutta-percha but is lower than Resilon. It is found that no matter in mechanical properties or thermal properties; ZnO/TPU composite has great potential in the root canal filling material. For the sealer resin part, visible-light photopolimerizable urethane-acrylate oligomer was synthesized and mixed with dilute monomer to form UA/TPGDA resin. The mechanical properties, relative molecule weight, viscosities, conversions, polymerization shrinkage, bonding strength, interface between sealer and dentin and antibacterial properties UA/TPGDA resin were investigated in this research. Results indicate that the viscosity of UA/TPGDA resin can be altered by the TPGDA content. The photoinitiator for UA/TPGDA (7/3 by wt.) is the mixture of camphorquinone and ethyl 4-dimethylaminobenzoate (1/2 by wt.) with concentration 3 phr. As for polymerization shrinkage, the UA/TPGDA resin with no filler even expands 5.72×10-3 % after curing. Even the strain of the UA/TPGDA (7/3 by wt.) resin with 40% filler content after curing is only -7.26×10-2 %. As for bonding strength, results show that bonding strength of the UA/TPGDA (7/3 by wt.) with 40wt% HEMA-modified nano-SiO2 and Composite H3 which were used as sealer and cone is the highest of all other groups of sealer and cone. From SEM photographs, urethane-acrylate based sealer with 40% filler is able to flow into dentin tube and be cured in side the tube and be mixed well. Furthermore, UA/TPGDA resin becomes antibacterial because being blended with chlorhexidine. It is found that visible-light curable urethane-acrylate oligomer has great potential in the root canal filling material sealer.