Department of Endodontology, Dental School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Int Endod J. 2018 Nov;51(11):1279-1291. doi: 10.1111/iej.12938. Epub 2018 Apr 30.
To evaluate setting time, pH, solubility and surface roughness of MTA+ and ProRoot MTA and characterize their hydration under several curing conditions.
Specimens were prepared to evaluate setting time (n = 6 for each group, specimen dimensions 10 × 8 × 5 mm), solubility (n = 6 for each group, specimen dimension 20 mm in diameter and 1.5 mm thick) after 1 and 28 days, pH (n = 10 for each group, specimen dimensions 10 mm in diameter and 1 mm thick) after 1, 7, 14, 21 and 28 days and surface roughness (n = 10 for each group, specimen dimensions 4 mm in diameter and 3 mm high) after 28 days when cements were cured at 95% humidity or immersed in saline or HBSS at 37 °C. The powder and liquid were mechanically mixed by an amalgamator. The set materials were characterized using X-ray diffraction analysis, scanning electron microscopy and X-ray energy-dispersive analysis. Statistical comparisons were employed using one-way anova. The level of significance was set at P = 0.05.
Setting time was significantly shorter when cements were cured at 95% humidity compared to those in saline (P < 0.001) and HBSS (P < 0.001). Setting time of MTA+ was significantly shorter than that of ProRoot MTA (P < 0.001), which had a significantly higher pH than MTA+ (P < 0.05) for all periods and immersion liquids. After immersion in saline, MTA+ was significantly less soluble than ProRoot MTA (P < 0.001); when immersed in HBSS, no significant difference was found (P = 1.00). The surface roughness of both cements was affected when exposed to HBSS (P < 0.001 for both cements) and saline (P < 0.001 for both cements). Storage in HBSS created a homogenous surface; incubation in saline or humidity created a biphasic surface. The main crystalline phases in both cements were tricalcium silicate, bismuth oxide and calcium hydroxide.
MTA+ had a shorter setting time than ProRoot MTA, promoted lower pH and had lower solubility in saline. Curing conditions affected the surface roughness and microstructure of the cements.
评估 MTA+和 ProRoot MTA 的凝固时间、pH 值、溶解度和表面粗糙度，并在几种固化条件下对其水化作用进行表征。
分别对每组各 6 个样本（试件尺寸 10×8×5mm）进行凝固时间评估，每组各 6 个样本（试件直径 20mm，厚度 1.5mm）进行 1 天和 28 天后的溶解度评估，每组各 10 个样本（试件直径 10mm，厚度 1mm）进行 1、7、14、21 和 28 天后的 pH 值评估，每组各 10 个样本（试件直径 4mm，高度 3mm）进行 28 天后的表面粗糙度评估，当水泥在 95%湿度下固化或在 37°C 下浸泡在盐水中或 HBSS 中时。粉末和液体通过混合器机械混合。使用 X 射线衍射分析、扫描电子显微镜和 X 射线能量色散分析对凝固材料进行了特征描述。采用单向方差分析进行统计学比较。显著性水平设定为 P=0.05。
与在盐水中（P<0.001）和 HBSS 中（P<0.001）相比，水泥在 95%湿度下固化时凝固时间明显缩短。MTA+的凝固时间明显短于 ProRoot MTA（P<0.001），且在所有时期和浸泡液中，MTA+的 pH 值均明显高于 ProRoot MTA（P<0.05）。在盐水中浸泡后，MTA+的溶解度明显低于 ProRoot MTA（P<0.001）；在 HBSS 中浸泡时，未发现明显差异（P=1.00）。暴露于 HBSS 时，两种水泥的表面粗糙度均受到影响（两种水泥均 P<0.001）；暴露于盐水中时，表面粗糙度也受到影响（两种水泥均 P<0.001）。在 HBSS 中储存会产生均匀的表面；在盐水中或湿度中孵育会产生双相表面。两种水泥的主要晶体相均为硅酸三钙、氧化铋和氢氧化钙。
MTA+的凝固时间短于 ProRoot MTA，在盐水中 pH 值较低，溶解度较低。固化条件会影响水泥的表面粗糙度和微观结构。
