Niakan Mahsa, Mosharraf Ramin
Dental Student Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Department of Prosthodontics, Dental Material Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
J Indian Prosthodont Soc. 2017 Oct-Dec;17(4):381-387. doi: 10.4103/jips.jips_36_17.
The aim of this study was to investigate the effect of timing of coronal preparation on the pushout bond strength of fiber postluted with resin cement in the root canal.
In this experimental study, 48 mandibular human premolars were selected in a 3-week range. After root canal treatment and postspace preparation, a post #2(Angelus, Brazil) was cemented into the canal by a resin-based cement (Bifix SE, VOCO, Germany). Cylindrical resin composite cores were built on the posts. Then, the specimens were divided into 4 groups of 12 specimens each: one control group without core preparation and 3 experimental groups with core preparation that was done 15 min, 1 h, and 24 h after postcementation. One day after postcementation, each root was sectioned into 3 segments. Each slice was connected to universal testing machine. The load was applied at the speed of 0.5 mm/min till failure happened. The collected data were analyzed (SPSS/PC 20.0; SPSS Inc., Chicago, IL, USA) using two-way ANOVA and Tukey test at < 0.05 level of significance.
Mean shear bond strength differences among interventional groups were not statistically significant ( > 0.05). Nevertheless, there were significant differences among root regions ( < 0.001).
It was concluded that core preparation and its timing does not affect adversely retention of fiber post and bond strength is higher in the cervical segment.
本研究旨在探讨根管内牙冠预备时机对用树脂水门汀粘结的纤维桩推出粘结强度的影响。
在本实验研究中,选取了3周内的48颗下颌人类前磨牙。根管治疗和桩道预备后,用树脂水门汀(德国VOCO公司的Bifix SE)将2号桩(巴西安热卢斯公司)粘结到根管内。在桩上制作圆柱形树脂复合核。然后,将标本分为4组,每组12个标本:1个不进行核预备的对照组和3个进行核预备的实验组,核预备分别在桩粘结后15分钟、1小时和24小时进行。桩粘结一天后,将每个牙根切成3段。将每片连接到万能试验机上。以0.5毫米/分钟的速度施加负荷直至发生破坏。使用双向方差分析和Tukey检验(美国伊利诺伊州芝加哥市SPSS公司的SPSS/PC 20.0)对收集的数据进行分析,显著性水平为<0.05。
各干预组之间的平均剪切粘结强度差异无统计学意义(>0.05)。然而,根区域之间存在显著差异(<0.001)。
得出的结论是,核预备及其时机不会对纤维桩的固位产生不利影响,且颈部区域的粘结强度更高。