Ma Yu-Qi, Liang Yu-Hong
Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices& Beijing Key Laboratory of Digital Stomatology & NHC Key Laboratory of Digital Stomatology & NMPA Key Laboratory for Dental Materials, Beijing, China.
Department of Stomatology, Peking University International Hospital, Beijing, China.
J Dent Sci. 2025 Jan;20(1):286-291. doi: 10.1016/j.jds.2024.07.014. Epub 2024 Jul 25.
BACKGROUND/PURPOSE: The obturation of canals with irregular structures is still a challenge for single cone obturation technique (SC). The purpose of this study was to evaluate the presence and distribution of voids using SC with different sealer placement methods in the canal with a simulated band-shaped isthmus.
3D-printed root canal models with band-shaped isthmuses were randomly divided into four groups according to different obturation methods. Group 1: sealer placement by single cone passively (SCP); Group 2: bi-directional spiral-supported sealer placement (BS); Group 3: ultrasound-supported sealer placement (U). Group 4: vertical compaction obturation (VC). In each group, 10 of 14 models were sliced and the remaining four were scanned by micro-CT. The percentage area of voids (PAV) and the percentage volume of voids (PVV) of fillings were calculated.
At all slice levels, using BS and U to support sealer placement reduced voids with an average PAV of 21%, and in the VC and SCP groups were 33% and 45% respectively. Based on the micro-CT scans, nearly half of the porosity decreased by the BS and ultrasound in the isthmus with PVV of 25% and 29% respectively, compared with 46% in the SCP group. However, in the main canal, when the PVV was 22% in the SCP group, the porosity decreased to 14% in the U group and 18% in the BS group.
Bi-directional spiral or ultrasound-supported sealer placement can improve the performance of single cone obturation in canals with an isthmus.
背景/目的：对于单锥充填技术（SC）而言，充填具有不规则结构的根管仍是一项挑战。本研究的目的是使用不同的封闭剂放置方法，通过单锥技术评估模拟带状峡部根管内空隙的存在情况及分布。
将具有带状峡部的3D打印根管模型根据不同的充填方法随机分为四组。第1组：单锥被动放置封闭剂（SCP）；第2组：双向螺旋辅助封闭剂放置（BS）；第3组：超声辅助封闭剂放置（U）。第4组：垂直加压充填（VC）。每组中，14个模型中的10个被切片，其余4个通过显微CT扫描。计算充填物的空隙面积百分比（PAV）和空隙体积百分比（PVV）。
在所有切片水平，使用BS和U辅助封闭剂放置可减少空隙，平均PAV为21%，而VC组和SCP组分别为33%和45%。基于显微CT扫描，在峡部，BS组和超声组的孔隙率分别降低了近一半，PVV分别为25%和29%，而SCP组为46%。然而，在主根管中，当SCP组的PVV为22%时，U组的孔隙率降至14%，BS组降至18%。
双向螺旋或超声辅助封闭剂放置可提高单锥技术在有峡部根管中的充填性能。
