López Fernanda Ullmann, Fachin Elaine Vianna, Camargo Fontanella Vania Regina, Barletta Fernando Branco, Só Marcus Vinícius Reis, Grecca Fabiana Soares
School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
J Endod. 2008 Dec;34(12):1545-8. doi: 10.1016/j.joen.2008.07.027. Epub 2008 Oct 18.
This study conducted an in vitro analysis of the level of apical transportation in mesiobuccal roots of upper molars after manual instrumentation with stainless steel files, preparation with the K3 system, and with a reciprocating NSK handpiece. Sixty roots were mounted in muffles and then longitudinally sectioned. A digital image was acquired of the inner surface of one root half. After instrumentation, the inner surfaces of the same root halves were digitized with file sizes #30, #35, and #40. Each image obtained was superimposed over the corresponding preoperative image, and the apical transportation was measured. The Friedman and Wilcoxon tests were used to compare results for the file sizes, and comparison of the groups was made with the Kruskal-Wallis test, demonstrating statistically significant differences (P = .000). The stainless steel file sizes #35 and #40 caused significant apical transportation, and K3 system proved safe for apical preparation, with little deviation.
本研究对使用不锈钢锉手动预备、K3系统预备以及使用NSK往复式手机预备后的上颌磨牙近中颊根根尖偏移水平进行了体外分析。将60颗牙根安装在马弗炉中，然后进行纵向切片。获取其中一个半根内表面的数字图像。预备后，使用#30、#35和#40号锉对同一半根的内表面进行数字化处理。将获得的每张图像叠加在相应的术前图像上，并测量根尖偏移。采用Friedman检验和Wilcoxon检验比较不同锉号的结果，采用Kruskal-Wallis检验比较各组结果，结果显示差异具有统计学意义（P = .000）。#35和#40号不锈钢锉导致明显的根尖偏移，而K3系统被证明用于根尖预备是安全的，偏差很小。
