- 學位論文
三鈣鋁酸含量對鈣矽陶瓷的材料性質及生物特性之影響
Effect of tricalcium aluminate on material properties, bioactivity and biocompatibility of calcium silicate ceramics
摘要
牙髓為具有修復再生能力的組織，活髓治療目的在治療任何具可回復性的牙髓傷害，將尚未受損的牙髓以合適的材料保護之，以避免任何外來的刺激。目前應用在臨床上成功率最高的活髓材料為MTA，以其有良好的生物相容性、可誘導牙本質再生、對於牙髓組織刺激小等性質，然而MTA的硬化時間長，需二次約診才可完成治療且操作性質差等缺點仍有待改進。 本實驗材料與目前成功率最高的MTA同樣是以C3S/C3A兩種成分為主的鈣矽陶瓷系統，希望藉由調整成分比例(90/10、70/30、50/50)來找出具有適合活髓治療的材料性質與生物特性的組成，並可評估不同比例的C3A對於材料性質、生物活性、生物相容性、增加細胞礦化能力等影響，作為日後發展新材料的依據；而材料的製備也參考本團隊之前所研發的溶膠凝膠法之化學製程，以期製造出更均質、反應性更佳的材料。 實驗主要分為三部分：(一)材料的研發：使用溶膠凝膠技術製備組成比例不同的材料並進行材料性質測試：以X光繞射分析材料結晶相、掃瞄式電子顯微鏡觀察材料表面結構、水合行為、硬化時間、抗壓強度、表面微硬度等；(二)體外生物活性指標測試；(三)生物相容性及鈣化能力：以MTT assay進行細胞毒性測試，以ALP assay及Alizarin test評估細胞鈣化能力。 C3A比例的增加有效縮短材料的硬化時間，但70/30、50/50的組別同時會減低材料機械強度，然而早期(一天)的表面微硬度則會上升，10%的組別則與市售MTA無顯著差異。所有材料組別皆有生物活性、鹼性磷酸酶活性及礦化小體的生成，然而表現上組別90/10與市售MTA優於組別50/50與70/30。此外，組別90/10除了與市售MTA擁有同樣優異的生物表現之外，以溶膠凝膠法製備更讓此材料具較高的反應性，初硬化時間顯著較市售MTA減少，所以作為活髓治療材料具相當潛力。
並列摘要
In dentistry, the goal of vital pulp therapy involves removing diseased pulp tissue and covering the remaining undamaged tissue with appropriate materials to induce pulp regeneration. Although plausible clinical results could often be achieved, the actual mechanism of pulp-dentin repair is still unknown. New materials need to be developed for reliable prognosis. The purpose of this study was to examine the physico-chemical properties and biological performances of novel calcium silicate biomaterials prepared from mixing different ratio of tricalcium silicate(C3S) and tricalcium aluminate(C3A) which aimed to improve the setting time which was compared with that of ProRoot white MTA without any change in biological properties. This study contained three experimental groups which contain C3S and C3A with different ratio (C3S/C3A: 90/10, 70/30, 50/50) and were fabricated with sol-gel technique; white-colored ProRoot MTA (Dentsply) was comparable group. The setting times, micro-hardness value, morphology and phase composition of hydration products and ex vivo bioactivity were evaluated, as well as the biocompatibility and mineralization, which use of MTT assay to evaluate cytotoxicity and use of ALP assay and Alizarin test to evaluate mineralization. As solid phases determined by XRD, the material powder with different C3A content were proved. The initial setting times of 70/30, 50/50 groups were in the range of 10-25 minutes, which are significantly (p<0.05, ANOVA and post-hoc test) lower than those obtained for white-colored ProRoot MTA (165 minutes) and 90/10 group(81 minutes). The micro-hardness of 50/50 and 70/30 were also significantly(p<0.05) higher than ProRoot MTA in the first day. All groups demonstrated ex vivo bioactivity when they came into contact with phosphate ions. The biocompatibility results of all groups were as good as the negative control except 50/50 with mild cytotoxicity. Results of mineralization test showed that all groups could induce hard tissue formation. Then we concluded in this study that, first, 90/10 group has optimal compressive strength, biocompatibility, and mineralization ability. Moreover, its material property is more reactive than white MTA. Second, with C3A increased to 30% to 50% in calcium silicate ceramics significantly improved setting time and early microhardness of the material, however, also exacerbating its material strength and biological properties.