Formosa L M, Mallia B, Camilleri J
Department of Metallurgy and Materials Engineering, Faculty of Engineering, University of Malta, Msida, Malta.
Int Endod J. 2014 May;47(5):454-62. doi: 10.1111/iej.12169. Epub 2013 Aug 6.
Assessment of the push-out bond strength of four MTA-based formulations for use as root-end filling materials.
MTA Plus mixed with (i) water ('MTA-W'); (ii) a proprietary water-based antiwashout gel ('MTA-AW'); (iii) Superbond C&B chemically curing resin ('MTA-Chem'); and (iv) Heliobond light-curing resin ('MTA-Light') was tested. Root slices 3 mm thick human had a 1.5 mm diameter hole drilled centrally and were treated with 17% EDTA for 60s. Forty specimens divided into groups 1-4 were prepared and filled with MTA-W, MTA-AW, MTA-Chem and MTA-Light, respectively. Groups 3 and 4 were etched with 37% phosphoric acid for 60s, and bonding agent was applied to the dentine surface. Specimens were stored for 28 days in Hanks' Balanced Salt Solution at 37 °C. Push-out strength was tested with a punch and die (punch diameter 1.3 mm, die diameter 2.0 mm, punch speed 1 mm min(-1)). Stereomicroscopy was used to classify failure mode (adhesive, cohesive or mixed type).
The resulting push-out strengths were 5.1 MPa (MTA-W), 4.3 MPa (MTA-AW), 4.7 MPa (MTA-Chem) and 11.0 MPa (MTA-Light). MTA-W had higher push-out strength than MTA-AW (P = 0.022). The same was noted for MTA-Light relative to the other materials (P < 0.05). All materials exhibited adequate push-out strengths compared with MTA-W. Failure was predominantly mixed, except for MTA-Chem (predominantly adhesive).
All materials exhibited adequate push-out strength. Previous studies have shown the new formulations have additional advantages including increased washout resistance and faster setting time, making them promising for future dental applications.
评估四种用作根尖充填材料的基于MTA的配方的推出粘结强度。
测试了与以下物质混合的MTA Plus：（i）水（“MTA-W”）；（ii）一种专有的水基防冲刷凝胶（“MTA-AW”）；（iii）Superbond C&B化学固化树脂（“MTA-Chem”）；以及（iv）Heliobond光固化树脂（“MTA-Light”）。对3毫米厚的人牙根切片在中心钻一个直径1.5毫米的孔，并用17%的EDTA处理60秒。制备40个标本并分为1-4组，分别用MTA-W、MTA-AW、MTA-Chem和MTA-Light进行充填。第3组和第4组用37%的磷酸蚀刻60秒，并在牙本质表面涂布粘结剂。标本在37℃的汉克斯平衡盐溶液中保存28天。用冲头和模具（冲头直径1.3毫米，模具直径2.0毫米，冲头速度1毫米/分钟）测试推出强度。使用立体显微镜对失效模式（粘结、内聚或混合型）进行分类。
得到的推出强度分别为5.1兆帕（MTA-W）、4.3兆帕（MTA-AW）、4.7兆帕（MTA-Chem）和11.0兆帕（MTA-Light）。MTA-W的推出强度高于MTA-AW（P = 0.022）。MTA-Light相对于其他材料也有同样情况（P < 0.05）。与MTA-W相比，所有材料都表现出足够的推出强度。除MTA-Chem（主要为粘结型）外，失效主要为混合型。
所有材料都表现出足够的推出强度。先前的研究表明，新配方具有其他优点，包括增强的抗冲刷性和更快的凝固时间，使其在未来牙科应用中具有前景。
