College of Dentistry, Conservative Department, University of Sulaimani, Madame Mitterand Street 30, 46001, Sulaimani, Kurdistan Region, Iraq.
BMC Oral Health. 2021 Mar 2;21(1):90. doi: 10.1186/s12903-021-01446-x.
Radiographic analysis of tooth morphology is mandatory for accurate calibration of the degree of canal curvature angle and radiographic working length to its real dimensions in case difficulty assessment protocols. This study aimed to determine the impact of the degree of root canal curvature angle on maintaining the real working length and the original canal axis of prepared root canals using a reciprocating rotary instrumentation technique.
Radiographic image analysis was performed on 60 extracted single-rooted human premolar teeth with a moderate canal curvature (10°-25°) and severe canal curvature (26°-70°). Working length and longitudinal canal axis were determined using cone-beam computed tomography (CBCT) and digital periapical radiography. The real canal length was determined by subtracting 0.5 mm from the actual canal length. Root canals were prepared using the WaveOne Gold reciprocating file (Dentsply Maillefer, Ballaigues, Switzerland).
There was no significant relation of the degree of canal curvature angle to the accuracy of radiographic working length estimated on CBCT and digital periapical radiographic techniques (P > 0.05). Postinstrumentation changes in the original canal axis between moderate and severe canal curvature angles, assessed on CBCT and periapical digital radiographic images were statistically non-significant (P > 0.05).
A standardized digital periapical radiographic method performed similarly to the CBCT technique near to its true working length. No significant interaction exists between the diagnostic working length estimation, postoperative root canal axis modification, and the degree of canal curvature angle, using reciprocating rotary instrumentation technique.
在评估难度评估方案时，为了准确校准根管弯曲角度的程度和射线照相工作长度与其真实尺寸，必须对牙齿形态进行射线照相分析。本研究旨在确定使用往复式旋转仪器技术时根管弯曲角度的程度对保持真实工作长度和预备根管原始根管轴的影响。
对 60 颗具有中度根管弯曲（10°-25°）和重度根管弯曲（26°-70°）的单根人前磨牙进行射线照相分析。使用锥形束 CT（CBCT）和数字根尖射线照相术确定工作长度和纵向根管轴。实际根管长度通过从实际根管长度中减去 0.5 毫米来确定。使用 WaveOne Gold 往复式锉（Dentsply Maillefer，Ballaigues，瑞士）预备根管。
根管弯曲角度的程度与 CBCT 和数字根尖射线照相技术估计的射线照相工作长度的准确性之间没有显著关系（P > 0.05）。在 CBCT 和数字根尖射线照相图像上评估中度和重度根管弯曲角度之间原始根管轴的后器械变化在统计学上无显著性差异（P > 0.05）。
标准化的数字根尖射线照相方法在其真实工作长度附近与 CBCT 技术表现相似。使用往复式旋转仪器技术时，诊断工作长度估计，术后根管轴修改和根管弯曲角度之间没有明显的相互作用。
