Çapar İsmail Davut, Uysal Banu, Ok Evren, Arslan Hakan
Department of Endodontics, Faculty of Dentistry, İzmir Katip Çelebi University, İzmir, Turkey.
Department of Endodontics, Faculty of Dentistry, İzmir Katip Çelebi University, İzmir, Turkey.
J Endod. 2015 Feb;41(2):253-6. doi: 10.1016/j.joen.2014.10.012. Epub 2014 Nov 27.
The purpose of this study was to investigate the incidence of apical crack initiation and propagation in root dentin after several endodontic procedures.
Sixty intact mandibular premolars were sectioned perpendicular to the long axis at 1 mm from the apex, and the apical surface was polished. Thirty teeth were left unprepared and served as a control, and the remaining 30 teeth were instrumented with ProTaper Universal instruments (Dentsply Maillefer, Ballaigues, Switzerland) up to size F5. The root canals were filled with the single-cone technique. Gutta-percha was removed with drills of the Rebilda post system (VOCO, Cuxhaven, Germany). Glass fiber-reinforced composite fiber posts were cemented using a dual-cure resin cement. The fiber posts were removed with a drill of the post system. Retreatment was completed after the removal of the gutta-percha. Crack initiation and propagation in the apical surfaces of the samples were examined with a stereomicroscope after each procedure. The absence/presence of cracks was recorded. Logistic regression was performed to analyze statistically the incidence of crack initiation and propagation with each procedure.
The initiation of the first crack and crack propagation was associated with F2 and F4 instruments, respectively. The logistic regression analysis revealed that instrumentation and F2 instrument significantly affected apical crack initiation (P < .001). Post space preparation had a significant effect on crack propagation (P = .0004). The other procedures had no significant effects on crack initiation and propagation (P > .05).
Rotary nickel-titanium instrumentation had a significant effect on apical crack initiation, and post space preparation with drills had a significant impact on crack propagation.
本研究的目的是调查在进行若干牙髓治疗程序后，牙根牙本质中根尖裂纹起始和扩展的发生率。
60颗完整的下颌前磨牙在距根尖1mm处垂直于长轴进行切片，并将根尖表面抛光。30颗牙齿未做处理作为对照，其余30颗牙齿用ProTaper Universal器械（登士柏迈徕特，瑞士拜莱格）预备至F5号。采用单锥技术充填根管。用Rebilda桩系统（VOCO，德国库克斯港）的钻针去除牙胶。使用双固化树脂水门汀粘结玻璃纤维增强复合纤维桩。用桩系统的钻针取出纤维桩。去除牙胶后完成再治疗。在每个程序后，用体视显微镜检查样本根尖表面裂纹的起始和扩展情况。记录有无裂纹。进行逻辑回归分析，以统计学方式分析每个程序中裂纹起始和扩展的发生率。
首次裂纹的起始和裂纹扩展分别与F2和F4器械有关。逻辑回归分析显示，器械预备和F2器械对根尖裂纹起始有显著影响（P <.001）。桩道预备对裂纹扩展有显著影响（P =.0004）。其他程序对裂纹起始和扩展无显著影响（P >.05）。
旋转镍钛器械预备对根尖裂纹起始有显著影响，用钻针进行桩道预备对裂纹扩展有显著影响。
