Mestres G, Aguilera F S, Manzanares N, Sauro S, Osorio R, Toledano M, Ginebra M P
Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgy, Technical University of Catalonia, Barcelona, Spain; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain.
Int Endod J. 2014 Feb;47(2):127-39. doi: 10.1111/iej.12123. Epub 2013 May 3.
To characterize three radiopaque Magnesium Phosphate Cements (MPCs) developed for endodontic purposes.
Three experimental MPCs containing Bi2 O3 were formulated. The experimental cements, which consisted of mixtures of magnesium oxide with different phosphate salts, were characterized for setting time, injectability, porosity, compressive strength and phase composition. The long-term sealing ability of the experimental MPCs applied in single-rooted teeth as root canal filling material or as sealer in combination with gutta-percha was also assessed using a highly sensitive fluid filtration system. A mineral trioxide aggregate (MTA) cement was used as control. Statistical analysis was performed with two- or three-way analysis of variance (anova) and Tukey's test was used for comparisons.
The addition of 10 wt% Bi2 O3 within the composition of the MPCs provided an adequate radiopacity for endodontic applications according to ISO 6876 standard. The reaction products resulting from the MPCs were either struvite (MgNH4 PO4 ·6H2 O) or an amorphous sodium magnesium phosphate. The porosity of the three MPCs ranged between 4% and 11%. The initial setting time of the experimental cements was between 6 and 9 min, attaining high early compressive strength values (17-34 MPa within 2 h). All MPC formulations achieved greater sealing ability than MTA (P < 0.05) after 3 months, which was maintained after 6 months for two of the experimental cements (P < 0.05).
These MPCs had adequate handling and mechanical properties and low degradation rates. Furthermore, a stable sealing ability was demonstrated up to 6 months when using the cement both as root filling material and as sealer in conjunction with gutta-percha.
对三种用于牙髓病治疗的不透射线磷酸镁骨水泥（MPC）进行特性描述。
制备了三种含Bi2O3的实验性MPC。这些实验性骨水泥由氧化镁与不同磷酸盐的混合物组成，对其凝固时间、可注射性、孔隙率、抗压强度和相组成进行了表征。还使用高灵敏度流体过滤系统评估了作为根管充填材料应用于单根牙或与牙胶联合作为封闭剂的实验性MPC的长期封闭能力。使用矿物三氧化物凝聚体（MTA）骨水泥作为对照。采用双因素或三因素方差分析（anova）进行统计分析，并使用Tukey检验进行比较。
根据ISO 6876标准，在MPC组成中添加10 wt%的Bi2O3可为牙髓病应用提供足够的不透射线性。MPC产生的反应产物为鸟粪石（MgNH4PO4·6H2O）或无定形磷酸钠镁。三种MPC的孔隙率在4%至¹¹%之间。实验性骨水泥的初始凝固时间在6至9分钟之间，2小时内达到较高的早期抗压强度值（17 - 34 MPa）。3个月后，所有MPC配方的封闭能力均优于MTA（P < 0.05），其中两种实验性骨水泥在6个月后仍保持这一优势（P < 0.05）。
这些MPC具有良好的操作性和机械性能，降解率低。此外，当将该骨水泥既用作根管充填材料又与牙胶联合用作封闭剂时，在长达6个月的时间内都表现出稳定的封闭能力。
