Mortazavi Vajihesadat, Fathi Mohammadhossein, Katiraei Najmeh, Shahnaseri Shirin, Badrian Hamid, Khalighinejad Navid
Torabinejad Dental Research Center, Department of Operative Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Dent Res J (Isfahan). 2012 Mar;9(2):185-91. doi: 10.4103/1735-3327.95234.
With the aim of developing methods that could increase the fracture resistance of structurally compromised endodontically treated teeth, this study was conducted to compare the effect of three esthetic post systems on the fracture resistance and failure modes of structurally compromised and normal roots.
Forty five extracted and endodontically treated maxillary central teeth were assigned to 5 experimental groups (n=9). In two groups, the post spaces were prepared with the corresponding drills of the post systems to be restored with double taper light posts (DT.Light-Post) (group DT.N) and zirconia posts (Cosmopost) (group Zr.N). In other 3 groups thin wall canals were simulated to be restored with Double taper Light posts (DT.W), double taper Light posts and Ribbond fibers (DT+R.W) and Zirconia posts (Zr.W). After access cavity restoration and thermocycling, compressive load was applied and the fracture strength values and failure modes were evaluated. Data were analyzed using two-way ANOVA, Tukey and Fisher exact tests (P<0.05).
The mean failure loads (N) were 678.56, 638.22, 732.44, 603.44 and 573.67 for groups DT.N, Zr.N, DT.W, DT+R.W and Zr.w respectively. Group DT+R.W exhibited significantly higher resistance to fracture compared to groups Zr.N, DT.W and Zr.w (P<0.05). A significant difference was detected between groups DT.N and Zr.W (P=0.027). Zirconia posts showed significantly higher root fracture compared to fiber posts (P=0.004).
The structurally compromised teeth restored with double taper light posts and Ribbond fibers showed the most fracture resistance and their strengths were comparable to those of normal roots restored with double taper light posts. More desirable fracture patterns were observed in teeth restored with fiber posts.
为了开发能够提高牙髓治疗后结构受损牙齿抗折性的方法，本研究旨在比较三种美学桩系统对结构受损牙根和正常牙根的抗折性及失效模式的影响。
45颗拔除并经牙髓治疗的上颌中切牙被分为5个实验组（n = 9）。在两组中，使用相应桩系统的钻头制备桩道，分别用双锥度轻型桩（DT.Light - Post）（DT.N组）和氧化锆桩（Cosmopost）（Zr.N组）进行修复。在另外3组中，模拟薄壁根管，分别用双锥度轻型桩（DT.W）、双锥度轻型桩和Ribbond纤维（DT + R.W）以及氧化锆桩（Zr.W）进行修复。在完成髓腔入口修复和热循环后，施加压缩载荷，并评估抗折强度值和失效模式。数据采用双向方差分析、Tukey检验和Fisher精确检验进行分析（P < 0.05）。
DT.N组、Zr.N组、DT.W组、DT + R.W组和Zr.w组的平均失效载荷（N）分别为678.56、638.22、732.44、603.44和573.67。与Zr.N组、DT.W组和Zr.w组相比，DT + R.W组表现出显著更高的抗折性（P < 0.05）。DT.N组和Zr.W组之间检测到显著差异（P = 0.027）。与纤维桩相比，氧化锆桩显示出显著更高的牙根折断率（P = 0.004）。
用双锥度轻型桩和Ribbond纤维修复的结构受损牙齿显示出最高的抗折性，其强度与用双锥度轻型桩修复的正常牙根相当。在用纤维桩修复的牙齿中观察到更理想的折断模式。
