Pereira Jefferson Ricardo, Valle Accácio Lins do, Shiratori Fábio Kenji, Ghizoni Janaina Salomon, Melo Murilo Pereira de
Department of Prosthodontics, Dental School, University of Southern Santa Catarina, Tubarão, SC, Brazil.
Braz Dent J. 2009;20(4):297-302. doi: 10.1590/s0103-64402009000400006.
The aim of this study was to investigate the fracture strength of endodontically treated teeth restored with different posts and variable ferrule heights. Sixty freshly extracted human canines were treated endodontically and randomly assigned to 6 groups (n=10), being restored with custom-made cast post-and-core (CP0 and CP3 groups), prefabricated post and composite resin core (PF0 and PF3 groups), and composite resin (CR0 and CR3 groups). The CP0, PF0 and CR0 groups presented no ferrule and the CP3, PF3 and CR3 presented 3 mm of coronal structure. All teeth were restored with full metal crowns. The fracture strength was measured in a universal testing machine at 45 degrees to the long axis of the tooth until failure. Data were analyzed statistically by 2-way ANOVA and Tukey's test (alpha=0.05). When the mean fracture strength values were compared (CP0 group - 820.20 N, CP3 group - 1179.12 N; PF0 group - 561.05 N; PF3 group - 906.79 N; CR0 group - 297.84 N; and CR3 group - 1135.15 N) there was statistically significant among the groups (p<0.05), except for the three groups with 3 mm of coronal remaining, which were similar to each other. The results of this study showed that the ferrule in crowns promoted significantly higher fracture strength in the endodontically treated teeth.
本研究的目的是调查用不同桩和不同龈缘高度修复的根管治疗牙的抗折强度。60颗新鲜拔除的人犬齿进行根管治疗，并随机分为6组（n = 10），分别用定制铸造桩核（CP0和CP3组）、预成桩和复合树脂核（PF0和PF3组）以及复合树脂（CR0和CR3组）进行修复。CP0、PF0和CR0组没有龈缘，CP3、PF3和CR3组有3mm的冠部结构。所有牙齿均用全金属冠修复。在万能试验机上以与牙长轴成45度角的方向测量抗折强度，直至牙齿折断。数据采用双向方差分析和Tukey检验进行统计学分析（α = 0.05）。比较平均抗折强度值时（CP0组 - 820.20N，CP3组 - 1179.12N；PF0组 - 561.05N；PF3组 - 906.79N；CR0组 - 297.84N；CR3组 - 1135.15N），除了剩余3mm冠部结构的三组之间相似外，各组之间存在统计学差异（p<0.05）。本研究结果表明，冠部的龈缘显著提高了根管治疗牙的抗折强度。
