Abstract：
The aim of this study was to evaluate how preset torque settings influence the torque, vertical force, and root canal-centering ability of ProGlider and ProTaper NEXT nickel-titanium rotary instruments in canals with different curvature locations. Based on micro-computed tomography, mesial roots of human mandibular molars (25°-40° curvature) were allocated to the apical curvature (apical 1-5 mm) or the middle curvature (apical 5-9 mm) groups, and mandibular incisors (curvature <5°) to the straight canal group. Each group was subjected to automated instrumentation and torque/force measurement with the preset torque of 1, 2.5, or 5 N•cm. Canal-centering ratios were determined with micro-computed tomography. Instrument fracture occurred only in the 2.5 and 5 N•cm groups in curved canals. The preset torque setting and curvature location did not influence canal shaping ability.
摘要：
这项研究的目的是评估预设扭矩设置如何影响扭矩，垂直力,ProGlider和ProTaperNEXT镍钛旋转器械在不同曲率位置的根管对中能力。基于显微计算机断层扫描，人类下颌磨牙的中根（25°-40°曲率）被分配到根尖曲率（根尖1-5毫米）或中间曲率（根尖5-9毫米）组，和下颌切牙（曲率<5°）到直管组。对每组进行自动化仪器和扭矩/力测量,预设扭矩为1、2.5或5N·cm。用显微计算机断层扫描确定运河中心比率。器械骨折仅发生在弯曲管的2.5和5N•cm组中。预设的扭矩设置和曲率位置不会影响运河成形能力。
