摻雜鍶介穩水泥混合半水硫酸鈣用於牙科活髓治療之研究

Abstract

Mineral trioxide aggregate (MTA) 作為活髓治療的材料，因具生物相容性、生物活性、封閉性質佳等優點而受到牙醫師的青睞，然而其硬化時間太長以及操作性不佳使其在臨床應用尚未達到理想。介穩水泥是本實驗室以MTA成分作為基礎所開發的材料，研究目的是以摻雜鍶的介穩水泥縮短硬化時間，以及利用鍶具有促進骨生成的特性刺激骨生成的效果，並加上半水硫酸鈣以改善介穩水泥的操作性。 介穩水泥摻雜5 mole% 鍶後初始硬化時間從30分鐘縮短至11分鐘，最終硬化時間從100分鐘縮短為34分鐘，相較於MTA初始硬化時間78分鐘以及最終硬化時間261分鐘縮短許多，搭配抗壓強度和微硬度兩者機械性質結果，顯示摻雜鍶介穩水泥犧牲部分機械性質，而得到較短的硬化時間；從XRD結果發現，水合後產物氫氧化鈣（Portlandite）18.2° 峰值以PSC-5Sr最為明顯，添加5 wt% 石膏會改善PSC-5Sr操作性，在體外實驗之礦化能力分析中，鹼性磷酸酶、鈣沉澱以及基因表現結果顯示摻雜鍶組別優於其他組別。綜合以上結果，本研究所研發摻雜鍶介穩水泥混合半水硫酸鈣具有短的硬化時間以及操作性，且在體外實驗之礦化分析具有促進骨生成相關蛋白質以及基因表現，顯示為相當具有潛力作為活髓治療的材料。

Mineral trioxide aggregate (MTA) has been used as a vital pulp material during vital pulp therapy for its good biocompatibility, bioactive and good sealing ability. However, several disadvantages of MTA have been reported such as long setting time, difficulty in handling. Our research group have developed material called Partial Stabilized Cement (PSC) which was based on MTA. The purpose of this study is focused on discussing the influences of strontium-doped PSC to shorten setting time and stimulate hard tissue formation, and adding calcium sulfate hemihydrates to improve handling property of PSC. 5 mole% of strontium were added to PSC. In this study, PSC-5Sr significantly decreased the initial setting time of PSC from 30 to 11 minutes and its final setting time from 100 to 34 minutes. PSC-5Sr had the highest intensity of the peak at the position of 18.2° for portlandite among those groups in XRD patterns of the hydration product for 4 hours, 1 and 7 days among these groups. The compressive strength and microhardness of PSC-5Sr were lower than other groups, which might relate to its shorter setting time. Next, handling properties of PSC-5Sr mixed with 5 weight% of calcium sulfate hemihydrates was improved. The result of ALP assay, Alizarin red S assay and gene expression indicated that PSC-5Sr promote MG63 cells to produce more alkaline phosphatase, calcium deposit and mineralized matrix related gene. In summary, the developed strontium doped partial stabilized cement mixed with calcium sulfate hemihydrates has great potential as a material for vital pulp therapy.