Department of Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, Brazil.
Universitary Center Unichistus, Fortaleza, Ceará, Brazil.
Braz Dent J. 2024 Mar 22;35:e245611. doi: 10.1590/0103-6440202405611. eCollection 2024.
This study evaluated the correlation between root canal curvature and the effects of ultrasonic irrigation in the following parameters: volume of uncontrolled dentin removal (UDRVol), maximum depth of dentin defects, removal of accumulated hard tissue debris (AHTD), and canal transportation in prepared curved root canals. Twenty-four human permanent mandibular molars were divided into two groups according to root canal curvature: moderate curvature (MC: mean 25°); and severe curvature (SC: mean 48°). The specimens were scanned using an X-ray microcomputed scanner (Skyscan 1172) before and after cleaning and shaping and after the final irrigation protocol with ultrasonic irrigation. There was a moderate correlation between the degree of root canal curvature and the volume of remaining AHTD (p<0.05) and between the degree of root canal curvature and maximum depth of defects due to uncontrolled removal of dentin (p<0.05). The teeth in the SC group had a greater maximum depth of defects on the dentin wall in the apical third than the teeth in the MC group (p <0.05). Both groups had a significant reduction of AHTD in all canal thirds, but the amount of remaining AHTD in the middle and apical thirds and the whole canal was significantly greater in the SC than in the MC group (p <0.05). Canal transportation was not influenced by the canal curvature in all thirds (p >0.05). This study concluded that root canal curvature affects significantly the uncontrolled removal of dentin and remaining AHTD volume after the final irrigation protocol with ultrasonic irrigation.
未控制牙本质去除量（UDRVol）、牙本质缺陷最大深度、累积硬组织碎屑去除（AHTD）和预备弯曲根管的根管偏移。根据根管弯曲度将 24 个人类下颌恒磨牙分为两组：中度弯曲（MC：平均 25°）；严重弯曲（SC：平均 48°）。在清洁和成型前后以及最后用超声冲洗冲洗后，使用 X 射线微计算机断层扫描仪（Skyscan 1172）对标本进行扫描。根管弯曲度与剩余 AHTD 量之间存在中度相关性（p<0.05），根管弯曲度与未控制牙本质去除引起的缺陷最大深度之间存在中度相关性（p<0.05）。与 MC 组相比，SC 组根尖三分之一牙本质壁上的缺陷最大深度更大（p <0.05）。两组在所有根管三分之一处的 AHTD 均显著减少，但 SC 组中根管中部和根尖三分之一处以及整个根管中剩余的 AHTD 量明显大于 MC 组（p <0.05）。在所有三分之一处，根管偏移不受根管弯曲度的影响（p >0.05）。本研究得出结论，根管弯曲度显著影响超声冲洗最后冲洗方案后牙本质的未控制去除和剩余 AHTD 量。
