Department of Anatomy, Faculty of Medicine and Surgery, University of Msida, Malta.
Department of Restorative Dentistry, Faculty of Dental Surgery, University of Msida, Malta.
J Endod. 2017 May;43(5):751-759. doi: 10.1016/j.joen.2016.12.022. Epub 2017 Mar 11.
Tricalcium silicate (TCS)-based materials are used in endodontics because they are hydraulic and interact with blood, tissue fluids, and phosphate-based root canal irrigants, resulting in biomineralization. Newer-generation materials are biphasic; calcium phosphate is added to the TCS; thus, the material has 2 cementitious phases. The effect of this addition is not known; thus, the aim of this study was to characterize biphasic cements and assess cellular proliferation and expression.
TCS cement mixed with calcium phosphate monobasic or hydroxyapatite in 1:1 proportion was prepared. The powders and the mixed cements soaked in Hank's balanced salt solution for 28 days were characterized by scanning electron microscopy (SEM), energy-dispersive spectroscopy, and X-ray diffraction analysis. Ion leaching was investigated using inductively coupled plasma mass spectroscopy. Cellular interaction with material leachate was investigated by exposing human primary osteoblasts to the leachate from the cements. Cell growth and proliferation were determined using methyltetrazolium assay and SEM.
The addition of a calcium phosphate phase to tricalcium silicate changed the material hydration with a reduction in pH and calcium ion release in the leachate when calcium phosphate monobasic was added. No crystalline calcium hydroxide was formed for both biphasic materials. The biphasic cements exhibited a reduction in cell growth and proliferation. SEM of the materials showed heavy carbonation of the material surface caused by processing for microscopy.
The addition of a second cementitious phase results in modification of the hydration characteristics of TCS cement with deterioration of material and biocompatibility properties.
硅酸三钙（TCS）基材料在牙髓学中被使用，因为它们是水硬性的，与血液、组织液和基于磷酸盐的根管冲洗液相互作用，导致生物矿化。新一代的材料是双相的；在 TCS 中添加了磷酸钙，因此，该材料具有 2 种胶凝相。这种添加的效果尚不清楚；因此，本研究的目的是对双相水泥进行特性描述，并评估细胞增殖和表达。
按 1:1 的比例制备 TCS 水泥与磷酸一钙或羟基磷灰石混合。将粉末和在 Hank's 平衡盐溶液中浸泡 28 天的混合水泥进行扫描电子显微镜（SEM）、能量色散光谱和 X 射线衍射分析。使用电感耦合等离子体质谱法研究离子浸出。通过将人原代成骨细胞暴露于水泥浸出液来研究材料浸出液与细胞的相互作用。通过噻唑蓝比色法和 SEM 测定细胞生长和增殖。
当添加磷酸一钙时，向硅酸三钙中添加钙磷相改变了材料的水合作用，导致 pH 值降低和浸出液中钙离子释放减少。两种双相材料均未形成结晶性氢氧化钙。双相水泥表现出细胞生长和增殖的减少。对材料进行 SEM 观察时，发现材料表面发生严重的碳化，这是由于处理用于显微镜观察所致。
添加第二胶凝相导致 TCS 水泥的水化特性发生变化，从而使材料和生物相容性恶化。
