Department of Endodontics, Faculty of Dentsity, Marmara University, Istanbul, Turkey.
Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
PLoS One. 2019 Nov 21;14(11):e0224793. doi: 10.1371/journal.pone.0224793. eCollection 2019.
To compare the efficiency of continuous wave obturation and cold lateral condensation techniques and filling time in C-shape canals of 3-dimensional (3D)-printed resin teeth shaped with Reciproc Blue (VDW) or Hyflex EDM (Coltene/Whaledent).
One tooth with C1-type orifice and root canal morphology and one with C2-type orifice and C2-C3 root canal morphology were selected based on CBCT. Two replicas of selected teeth were manufactured with a 3D-printer and their canals were instrumented with Reciproc Blue or Hyflex EDM. These 4 instrumented replicas were scanned with CBCT. Identical 10 replicas of each group (total of 40) were produced using a 3D-printer and randomly divided into 2 groups (n = 5), root filled with either continuous wave obturation (CW) or cold lateral condensation (LC). Horizontal cross-sections of C1-type were made at 2, 4, 6, 8 mm and C2-type at 2, 4, 6 mm from the apical foramen. Gutta-percha, sealer and void areas were evaluated with image analysis sofware. Data were analysed using nonparametric Kruskal-Wallis and Mann Whitney-U tests and the Factorial ANOVA was used for interaction effects. Time required to fill canals was evaluated using the Mann-Whitney U test.
For C1-type, LC had more gutta-percha and less sealer compared to CW in 2-mm sections (p<0.05). CW had greater percentages of gutta-percha and lower percentages of sealer compared with LC group in 4, 6, 8 mm sections and total area (p<0.05). LC group had higher percentages of voids compared to CW group in 2 and 4 mm sections (p<0.05). For C2-type, CW had more gutta-percha and less sealer versus LC group in all sections and total area (p<0.05). LC had the least gutta-percha and greatest sealer percentages at 6-mm sections (p<0.05). There was no statistically significant difference in the percentages of voids at any level of sections between the filling techniques (p>0.05). In both C-types, there was no significant difference in the percentages of gutta-percha, sealer and voids between Reciproc Blue and Hyflex EDM-shaped groups at any level (p>0.05). Time spent for the LC technique and filling C1-type was significantly longer than when using the CW technique and filling C2-type (p<0.05).
Continuous wave obturation was more effective than lateral condensation in both C1- and C2-type, except for the apical 2 mm section of C1-type, suggesting the need for a modified CW technique.
比较连续波根管充填技术和冷侧方加压技术在 3D 打印 Reciproc Blue（VDW）或 Hyflex EDM（Coltene/Whaledent）树脂牙 C 形根管中的效率和充填时间。
根据 CBCT 选择具有 C1 型口和根管形态的一颗牙和具有 C2 型口和 C2-C3 根管形态的一颗牙。用 3D 打印机制作两颗所选牙齿的复制品，并使用 Reciproc Blue 或 Hyflex EDM 对其根管进行仪器化。用 CBCT 对这 4 个仪器化的复制品进行扫描。使用 3D 打印机制作每组（共 40 个）各 10 个复制品，并随机分为 2 组（n = 5），分别用连续波根管充填（CW）或冷侧方加压（LC）根充。在距根尖孔 2、4、6、8mm 处制作 C1 型的水平横断面，在距根尖孔 2、4、6mm 处制作 C2 型的水平横断面。使用图像分析软件评估牙胶、密封剂和空隙区域。使用非参数 Kruskal-Wallis 和 Mann-Whitney-U 检验分析数据，并使用析因方差分析交互效应。使用 Mann-Whitney U 检验评估根管充填所需的时间。
对于 C1 型，在 2mm 切片中，LC 组的牙胶多于 CW 组，而密封剂少于 CW 组（p<0.05）。在 4、6、8mm 切片和总面积中，CW 组的牙胶百分比高于 LC 组，而密封剂百分比低于 LC 组（p<0.05）。LC 组在 2mm 和 4mm 切片中的空隙百分比高于 CW 组（p<0.05）。对于 C2 型，CW 组在所有切片和总面积中的牙胶多于 LC 组，而密封剂少于 LC 组（p<0.05）。在 6mm 切片中，LC 组的牙胶百分比最低，而密封剂百分比最高（p<0.05）。两种充填技术在各切片水平的空隙百分比均无统计学差异（p>0.05）。在两种 C 型中，在任何切片水平，Reciproc Blue 和 Hyflex EDM 成形组之间的牙胶、密封剂和空隙百分比均无统计学差异（p>0.05）。LC 技术的时间和 C1 型的充填时间明显长于 CW 技术和 C2 型的充填时间（p<0.05）。
连续波根管充填技术在 C1 型和 C2 型中均比冷侧方加压技术更有效，除了 C1 型根尖 2mm 切片外，这表明需要改进连续波根管充填技术。
