Physicochemical properties of calcium silicate-based formulations MTA Repair HP and MTA Vitalcem

Abstract Objective This study aimed to analyze the following physicochemical properties: radiopacity, final setting time, calcium release, pH change, solubility, water sorption, porosity, surface morphology, and apatite-forming ability of two calcium silicate-based materials. Material and methods We tested MTA Repair HP and MTA Vitalcem in comparison with conventional MTA, analyzing radiopacity and final setting time. Water absorption, interconnected pores and apparent porosity were measured after 24-h immersion in deionized water at 37°C. Calcium and pH were tested up to 28 d in deionized water. We analyzed data using two-way ANOVA with Student-Newman-Keuls tests (p<0.05). We performed morphological and chemical analyses of the material surfaces using ESEM/EDX after 28 d in HBSS. Results MTA Repair HP showed similar radiopacity to that of conventional MTA. All materials showed a marked alkalinizing activity within 3 h, which continued for 28 d. MTA Repair HP showed the highest calcium release at 28 d (p<0.05). MTA Vitalcem showed statistically higher water sorption and solubility values (p<0.05). All materials showed the ability to nucleate calcium phosphate on their surface after 28 d in HBSS. Conclusions MTA Repair HP and MTA Vitalcem had extended alkalinizing activity and calcium release that favored calcium phosphate nucleation. The presence of the plasticizer in MTA HP might increase its solubility and porosity. The radiopacifier calcium tungstate can be used to replace bismuth oxide.

摘要 目的 本研究旨在分析两种硅酸钙基材料的以下理化特性：放射阻射性、最终凝固时间、钙释放量、pH变化、溶解度、吸水率、孔隙率、表面形貌以及成磷灰石能力。
材料与方法 本研究以传统MTA（Mineral Trioxide Aggregate，矿物三氧化物凝聚体）为对照，测试MTA Repair HP与MTA Vitalcem，分析其放射阻射性与最终凝固时间。将材料置于37℃去离子水中浸泡24小时后，测定其吸水率、连通孔隙率与表观孔隙率。于去离子水中分别检测至28天的钙释放量与pH变化。采用双因素方差分析结合Student-Newman-Keuls检验对数据进行统计学分析，检验水准设为p<0.05。将材料置于HBSS（Hank's Balanced Salt Solution，汉克平衡盐溶液）中孵育28天后，采用环境扫描电子显微镜/能谱仪（ESEM/EDX，Environmental Scanning Electron Microscope/Energy Dispersive X-ray Spectroscopy）对材料表面进行形貌与化学分析。
结果 MTA Repair HP的放射阻射性与传统MTA相近。所有材料在3小时内均表现出显著的碱化活性，且该活性可持续至28天。MTA Repair HP在28天时的钙释放量最高（p<0.05）。MTA Vitalcem的吸水率与溶解度值在统计学上显著更高（p<0.05）。所有材料在HBSS中孵育28天后，其表面均具备磷酸钙成核能力。
结论 MTA Repair HP与MTA Vitalcem具有持久的碱化活性与钙释放能力，可促进磷酸钙成核。MTA HP中增塑剂的存在可能会提升其溶解度与孔隙率。阻射剂钨酸钙可替代氧化铋。