Private Practice, Fortaleza, CE, Brazil.
Department of Dentistry, Endodontics and Dental Materials, Bauru Dental School, University of São Paulo, Bauru, SP, Brazil.
Int Endod J. 2018 Jun;51(6):705-713. doi: 10.1111/iej.12881. Epub 2017 Dec 14.
To evaluate apical transportation and centring ability during root canal preparation in mesial root canals of mandibular molars associated with ProTaper Gold (PTG), ProDesign S (PDS), Hyflex CM (HCM), Hyflex EDM and ProDesign Logic (PDL).
Sixty mandibular first molars with two separate canals in the mesial root were selected after root anatomy pairing by microcomputed tomography (microCT). The teeth were randomly divided into five groups (n = 24); the root canal volume was calculated to ensure sample homogeneity. All the root canals were prepared up to size 25 in accordance with the instructions of each rotary system manufacturer. After root canal preparation, the teeth were scanned by microCT to analyse apical transportation, root canal centralization and the pre- and post-preparation root canal volume at the apical and cervical levels. Kruskal-Wallis and Dunn tests were used for comparisons amongst groups for transportation values. For volume changes, the parametric ANOVA and Tukey's tests were used RESULTS: There were no significant differences in apical transportation amongst the rotary systems (P > 0.05). All the systems created apical transportation; values ranging from 0.031 mm (PDL) to 0.072 mm (PTG), and enlargements between 39% (HCM) and 91.1% (PDS) were observed. In relative to cervical transportation, significant differences were observed amongst the systems (P < 0.05). Mean transportation values between 0.07 mm (HCM) and 0.172 mm (PTG) were found, with enlargements between 35.4% (HCM) and 51.5% (PDS).
All the thermally treated systems resulted in similar apical transportation. In the cervical region, the Hyflex CM and Prodesign Logic systems were associated with more centred preparations.
评估 ProTaper Gold（PTG）、ProDesign S（PDS）、Hyflex CM（HCM）、Hyflex EDM 和 ProDesign Logic（PDL）在磨牙近中根管预备时的根尖运输和根管中心定位能力。
通过 microCT（微计算机断层扫描）对根解剖配对后选择 60 颗具有近中两根管的下颌第一磨牙。将牙齿随机分为五组（n=24）；计算根管容积以确保样本均匀性。所有根管均按照每个旋转系统制造商的说明预备至 25 号。根管预备后，用 microCT 扫描牙齿，分析根尖运输、根管中心定位以及根尖和颈段预备前后根管容积的变化。使用 Kruskal-Wallis 和 Dunn 检验比较各组之间的运输值。对于体积变化，使用参数 ANOVA 和 Tukey 检验。
在旋转系统之间，根尖运输没有显著差异（P>0.05）。所有系统都造成了根尖运输；值范围从 0.031mm（PDL）到 0.072mm（PTG），扩张率从 39%（HCM）到 91.1%（PDS）不等。与颈向运输相比，系统之间存在显著差异（P<0.05）。发现的平均运输值在 0.07mm（HCM）和 0.172mm（PTG）之间，扩张率在 35.4%（HCM）和 51.5%（PDS）之间。
所有热处理系统都导致了类似的根尖运输。在颈区，Hyflex CM 和 ProDesign Logic 系统与更中心的预备有关。
