AIM To evaluate the use of a reduced taper endodontic instrument system (Bassi Logic™ .03 taper) and expandable heat-treated system (XP-endo Shaper) on the ability to shape canals in mandibular molars, by means of microcomputed tomography (micro-CT) analysis. The Reciproc system was used as the reference for comparison. METHODOLOGY Twenty-four mandibular molars were scanned in a micro-CT, matched based on similar anatomical features and sorted into three groups (n = 8 per group), according to root canal preparation system: Bassi Logic™ .03, XP-endo Shaper and Reciproc. The teeth were mounted onto a mannequin and the pulp chambers were accessed with traditional access cavities. In Bassi Logic™ .03 and Reciproc groups, mesial canals were prepared with size 25, .03 taper or R25 (size 25, .08v taper) instruments and the distal root canal with size 25, .03 taper and size 40, .03 taper or R25 and R40 (size 40, .06v taper), respectively. In XP-endo Shaper groups, all root canals were prepared with XP-endo Shaper (size 30, .04v taper). After root canal preparation, the teeth were rescanned. The percentage of untouched canal areas and the percentage of removed dentine were evaluated separately for mesial and distal root canals. The data were analysed using one-way anova and Tukey tests (P < 0.05). RESULTS The Bassi Logic™ .03 group was associated with a greater percentage of untouched canal areas when compared to XP-endo Shaper and Reciproc groups for mesial and distal root canals (P < 0.05), but no differences were found between XP-endo Shaper and Reciproc groups (P > 0.05). No significant difference was observed in the percentage of dentine removed amongst the groups for mesial and distal root canals (P > 0.05). CONCLUSION The use of a reduced taper system (Bassi Logic™ .03) during root canal preparation resulted in a greater percentage of untouched canal areas when compared to XP-endo Shaper and Reciproc instruments. No differences were observed amongst the systems regarding the percentage of dentine removed.

中文翻译：

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微创根管准备策略对下颌磨牙根管成形能力的影响。

目的评估通过微型计算机断层扫描（微型计算机断层扫描）在锥形下颌磨牙中对牙管进行成形的能力，以评估使用锥度减小的牙髓器械系统（Bassi Logic™.03锥度）和可扩展的热处理系统（XP-endo Shaper） CT）分析。Reciproc系统用作比较的参考。方法学根据根管预备系统：Bassi Logic™.03，XP-endo Shaper，在微型CT中扫描二十四个下颌磨牙，根据相似的解剖特征进行匹配，并分为三组（每组n = 8）。和倒数。将牙齿安装在人体模型上，并通过传统的出入腔进入牙髓腔。在Bassi Logic™.03和Reciproc组中，使用25号，.03锥度或R25（25号，.08v锥度）器械和25号，0.03锥度和40、0.03锥度或R25和R40（40、0.06v锥度）。在XP-endo Shaper组中，所有根管均用XP-endo Shaper（尺寸30，0.04v锥度）准备。准备好根管后，重新扫描牙齿。分别评估中，远端根管的未触及管区域的百分比和去除的牙质的百分比。使用单向方差分析和Tukey检验分析数据（P <0.05）。结果与XP-endo Shaper和Reciproc组的中，远侧根管相比，Bassi Logic™.03组与未触及的根管区域比例更高（P <0.05），但XP-endo Shaper之间没有差异和倒数组（P> 0.05）。在中，远端根管中，去除牙本质的百分比没有显着差异（P> 0.05）。结论与XP-endo Shaper和Reciproc器械相比，在根管准备过程中使用减少的锥度系统（Bassi Logic™.03）会导致未触及的根管区域百分比更高。在系统之间没有观察到关于去除的牙本质的百分比的差异。