Effect of obturation technique using a new bioceramic sealer on the presence of voids in flattened root canals

Abstract The aim of this study was to evaluate the filling ability of a new ready-to-use calcium silicate-based sealer using thermoplastic or single-cone technique in flattened root canals. Twenty-four flattened distal canals of mandibular molars with a buccolingual diameter 4 or more times larger than the mesiodistal diameter were selected. The root canals were prepared and filled (n = 12), according to the following techniques: thermoplastic or single-cone technique using Bio-C Sealer. The teeth were scanned using Skycan 1176 micro-computed tomography (micro-CT) - voxel size 8.74 µm, before and after filling the root canal. The percentage of voids in the filled root canals was evaluated, and the data were statistically analyzed using the unpaired t-test (α = 0.05). The root canals filled using the thermoplastic technique created a smaller percentage of voids in the cervical/middle thirds than those filled using the single-cone technique (p < 0.05). There was no difference in the percentage of voids using either technique in the apical third (p > 0.05). The flattened root canals in the cervical/middle thirds were better filled using the ready-to-use calcium silicate-based sealer associated to the thermoplastic technique, compared with the single-cone technique. In the apical third, the techniques showed similar filling ability.

摘要
本研究旨在评估一种新型预调配型硅酸钙基封闭剂（ready-to-use calcium silicate-based sealer）分别联合热塑充填技术与单尖充填技术，在扁平型根管中的充填效能。本研究选取24颗下颌磨牙的扁平型远中根管，其颊舌径为近远中径的4倍及以上。将根管预备后分为两组（每组n=12），分别采用以下两种充填方案：热塑充填技术联合Bio-C Sealer，或单尖充填技术联合Bio-C Sealer。分别于根管充填前后，使用Skycan 1176型显微计算机断层扫描（micro-computed tomography，micro-CT，体素尺寸8.74 µm）对离体牙进行扫描。评估充填后根管内空隙所占百分比，并采用独立样本t检验对数据进行统计学分析，检验水准设定为α=0.05。相较于单尖充填技术组，热塑充填技术组根管的颈/中段空隙占比更低，差异具有统计学意义（p<0.05）。而在根尖段，两种充填技术的空隙占比无统计学差异（p>0.05）。综上，相较于单尖充填技术，预调配型硅酸钙基封闭剂联合热塑充填技术可更优地完成扁平型根管颈/中段的充填；而在根尖段，两种技术的充填效能相当。