The objective of this study was to evaluate and compare the filling ability of various root canal obturation techniques on the internal root resorption (IRR) cavities of replicated tooth samples manufactured using computer software and a three-dimensional (3D) printer. Orthographic images and root structures of a healthy upper maxilla central incisor in determined volumes and sizes were drawn as a prototype with the aid of computer software. Using the same software, an IRR defect was also modeled. These two images were then transferred to the AutoDesk Fusion 360 3D modeling program (AutoDesk, San Rafael, CA) for meshing. Afterward, the tooth model was transferred to a 3D modeling and prototyping program (RhinoCeros 3D; Robert McNells & Assoc., New York) and printed on a 3D printer. Eighty replicas with IRR were manufactured and divided into four groups (n = 20 per group) according to the obturating techniques as follows: Group 1: Cold lateral compaction (CLC), Group 2: Core Carrier System (GuttaCore), Group 3: Injectable Cold Filling (GuttaFlow^® BioSeal), and Group 4: Continuous Wave Obturation System (Elements Free). After root canal filling, replicas were scanned with a high-resolution micro-computed tomography system (SkyScan 1172; Bruker-microCT, Kontich, Belgium), data regarding voids (unobturated areas) inside the IRR defects were statistically analyzed using nonparametric Kruskal–Wallis tests. A pairwise comparison between the tested groups showed that Groups 3 and 4 had significantly fewer voids compared with Groups 1 and 2 in IRR defects (p < 0.05). Group 1/Group 2 and Group 3/Group 4 had similar results in terms of voids and there were no statistically significant differences (p > 0.05). The injectable cold filling system (GuttaFlow BioSeal) and the injectable continuous wave obturation system (Elements Free) successfully obturated the pathological IRR irregularities when compared with CLC and core carrier (GuttaCore) systems.

中文翻译：

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计算机软件制作的三维打印牙齿内根吸收中不同根管充填技术的评价


本研究的目的是评估和比较各种根管充填技术对使用计算机软件和三维 (3D) 打印机制造的复制牙齿样本的内部牙根吸收 (IRR) 空腔的填充能力。借助计算机软件绘制确定体积和尺寸的健康上颌中切牙的正射图像和根结构作为原型。使用相同的软件，还对 IRR 缺陷进行了建模。然后将这两个图像传输到 AutoDesk Fusion 360 3D 建模程序（AutoDesk，圣拉斐尔，加利福尼亚州）进行网格划分。随后，牙齿模型被转移到 3D 建模和原型制作程序（RhinoCeros 3D；Robert McNells & Assoc.，纽约）并在 3D 打印机上打印。制作了 80 个 IRR 复制品，并根据填充技术分为四组（每组n = 20）：第 1 组：冷横向压实 (CLC)，第 2 组：核心载体系统 (GuttaCore)，第 3 组：可注射冷灌装 (GuttaFlow ^® BioSeal) 和第 4 组：连续波充填系统（无元素）。根管充填后，使用高分辨率微型计算机断层扫描系统（SkyScan 1172；Bruker-microCT，Kontich，比利时）扫描复制品，使用非参数 Kruskal-Wallis 对 IRR 缺陷内空隙（未封闭区域）的数据进行统计分析测试。测试组之间的两两比较表明，与第 1 组和第 2 组相比，第 3 组和第 4 组的 IRR 缺陷空隙明显减少 ( p < 0.05)。第 1 组/第 2 组和第 3 组/第 4 组在空隙方面具有相似的结果，并且没有统计学显着差异 ( p > 0.05)。 与 CLC 和核心载体 (GuttaCore) 系统相比，可注射冷填充系统 (GuttaFlow BioSeal) 和可注射连续波封闭系统 (Elements Free) 成功封闭了病理性 IRR 不规则性。