Mokhtari Hadi, Jafarizadeh Sara, Mokhtari Zonouzi Hamid Reza, Lotfi Mehrdad, Forough Reyhani Mohammad, Sohrabi Aydin
Department of Endodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
Department of Orthodontics, Dental School, Tabriz University of Medical Sciences, Tabriz, Iran.
Iran Endod J. 2017 Summer;12(3):293-297. doi: 10.22037/iej.v12i3.15600.
Mineral trioxide aggregate (MTA) can be used in the treatment of irritated vital pulp and repair of root perforations. However, the initial reaction of inflammatory cells to this material and also its setting time are not ideal. Studies have shown that disodium hydrogen phosphate (DHP), decreases the setting time of MTA, with no effect on its pH. This study was undertaken to evaluate the effect of DHP on push-out bond strength of MTA at different liquid-to-powder ratios.
A total of 120 samples were prepared from the middle third of the roots of single-rooted teeth for evaluation of push-out bond strength. The push-out bond strength was measured in both groups after 72 h at different liquid-to-powder ratios, including 0.33:1, 0.5:1 and 0.6:1. Factorial ANOVA and Tukey's HSD post-hoc tests were used to compare the differences between the independent groups. Statistical significant was set at <0.05.
The push-out bond strengths of pure MTA and MTA+DHP groups were 10.96±5.78 and 13.32±5.03, respectively. Tukey's HSD post-hoc test revealed significant differences between the two groups. Furthermore, there were no interactive effect between material and the liquid: powder ratio.
Incorporation of DHP into MTA resulted in an increase in push-out bond strength of MTA, and an increase in liquid-to-powder ratio resulted in a decrease in push-out bond strength.
矿物三氧化物凝聚体（MTA）可用于治疗激惹的活髓和修复根穿孔。然而，炎症细胞对这种材料的初始反应及其凝固时间并不理想。研究表明，磷酸氢二钠（DHP）可缩短MTA的凝固时间，且对其pH值无影响。本研究旨在评估DHP在不同液粉比下对MTA推出粘结强度的影响。
从单根牙牙根中部三分之一处制备120个样本，用于评估推出粘结强度。在72小时后，于不同液粉比（包括0.33:1、0.5:1和0.6:1）下测量两组的推出粘结强度。采用析因方差分析和Tukey's HSD事后检验比较独立组之间的差异。统计学显著性设定为<0.05。
纯MTA组和MTA+DHP组的推出粘结强度分别为10.96±5.78和13.32±5.03。Tukey's HSD事后检验显示两组之间存在显著差异。此外，材料与液粉比之间没有交互作用。
在MTA中加入DHP可提高MTA的推出粘结强度，而液粉比的增加会导致推出粘结强度降低。
