新型幾丁聚醣水膠應用於乳齒根管封填之研發

Development of a novel chitosan based thermosensitive hydrogel as a root filling material for primary teeth

高子揚(Tzu-Yang Kao)

指導教授 ： 林俊彬

共同指導教授 ： 王姻麟(Yin-Lin Wang)

國立臺灣大學/醫學院/臨床牙醫學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202104384

摘要

乳齒根管的治療有間接覆髓(indirect pulp treatment)、直接覆髓(direct pulp cap)、斷髓(pulpotomy)、拔髓(pulpectomy)。臨床上若因齲齒或是外傷侵犯到牙髓牙本質複合體(pulp-dentin complex)，進一步就會造成不可逆牙髓炎或是牙髓壞死，此時就必需進行拔髓治療，以達成保存乳齒，使其留存至自然生理性脫落。因此要達到成功的乳齒拔髓治療，根管封填材料就扮演了不可或缺的重要角色。
臨床上理想的乳齒根管封填材料希望可以滿足：與牙根生理性吸收之速率相近、可抑制細菌、臨床操作易於填充、不會造成牙齒變色等等條件。現有臨床常用於乳齒根管填充之碘仿氫氧化鈣預拌糊雖然臨床操作性質良好，但過往研究顯示卻顯示其具有抑制細菌能力不佳、生理性吸收過於快速、造成牙齒變色之缺點。本研究的目的於利用幾丁聚醣的良好抗菌表現以及生物相容性，為了增強幾丁聚醣的抗菌效果與其功能性，本研究使用快速研磨機進行研磨，使其成為微米化，可增加表面積使其暴露出較多之官能基(NH3+, OH-)，可增加與高分子反應的交聯程度，也可提升生物吸收的特性，並挑選最適化，採用離子交聯法將幾丁聚醣/β甘油磷酸鈉製備成溫敏性水膠。期望能以此為基礎發展，分析做為新型乳齒根管封填材料，改良現有臨床常用乳齒根管填充材的缺點。
本研究分為三部分，第一部分利用快速球磨機進行幾丁聚醣研磨後，由掃描式電子顯微鏡觀察粉末表面型態，並以動態雷射光散射分析粒徑大小與分佈。根據實驗結果顯示以研磨時間120分鐘可獲得最適化之幾丁聚醣粉末，且其粒徑分布最均勻，並以傅立葉轉換紅外線光譜分析粉末表面官能基，其結果顯示以快速球磨機研磨幾丁聚醣，是一個簡易且不會造成樣品化學性質破壞，使幾丁聚醣成為次微米化的方法。第二部分以動態機械分析幾丁聚醣/β甘油磷酸鈉溫敏性水膠之成膠溫度與成膠時間，結果顯示，利用溫敏性水膠最佳參數為幾丁聚醣濃度3%與β甘油磷酸鈉350 mg/mL調配成之溫敏性水膠，可以在室溫時保持液相，並在接近而略低於人體生理溫度時凝膠化。第三部分則以直接接觸法進行抑菌圈測試，並以Alamar Blue cell viability assay 測試生物相容性，根據實驗結果得知，幾丁聚醣/β甘油磷酸鈉溫敏性水膠展現出良好的抗菌性以及生物相容性，具有良好潛力作為乳齒根管填充材料之候選材料。

關鍵字

乳齒根管封填材料 ； 幾丁聚醣 ； 溫敏性水膠 ； 根管治療 ； 抗菌材料

並列摘要

Pulp therapy for primary teeth includes: indirect pulp treatment, direct pulp cap, pulpotomy and pulpectomy. If caries lesion invades into pulp-dentin complex and induces irreversible pulpitis or pulp necrosis, pulpectomy is indicated to preserve primary teeth for them to keep normal function and normally shed. In practice, root filing materials play important roles for clinicians to perform pulpectomy successfully.
Ideally, a root filling material for primary teeth should be resorbed at the same pace as the physiologic resorption of the roots, antiseptic, easy to insert into root canals, and will not induce teeth to discoloration. A mixed paste of calcium hydroxide and iodoform (Vitapex) is widely used among dentists and has become mainstream nowadays for it is easy to handle clinically. However, past studies showed the disadvantages of this product: poor antiseptic ability, being physiologic resorbed too rapidly, and discoloration to the teeth. Previously, a modified chitosan-based material from our research team not only was improved for its ability to carry fluoride, but also showed the significant antibacterial property. Thus, the purpose of this research is to take advantage of the outstanding antibacterial ability and excellent biocompatibility of chitosan to synthesize a chitosan-based thermosensitive hydrogel for a potential candidate for primary root filling material.
This research comes into three parts. The results from the first part showed that a ball grinder could be used to grind after-market chitosan powers into a sub-micron scale without pulverizing it. The results from the second part revealed the proper recipe for synthesizing chitosan/ βGP thermosensitive hydrogel for gelation point around human body temperature. The results from the third part showed that the chitosan/ βGP thermosensitive hydrogel synthesized in this experiment had both excellent antimicrobial ability and great biocompatibility. Thus, the chitosan/ βGP thermosensitive hydrogel had great potential to be a promising candidate for root canal filling material for primary tooth.

並列關鍵字

root canal filling material ； primary tooth ； chitosan ； thermosensitive hydrogel ； root canal therapy ； pulpectomy ； antimicrobial material

參考文獻

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