Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
School of Dentistry, University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil.
J Endod. 2021 Jun;47(6):989-999. doi: 10.1016/j.joen.2021.03.009. Epub 2021 Mar 25.
The purpose of this study was to evaluate the impact of conservative endodontic cavities (CECs) on root canal preparation, restoration, and biomechanical behavior of teeth prepared using different shaping systems and restorative materials.
Ninety upper premolars with a bifurcated root were matched based on morphology and randomly assigned to a control group (n = 10) or 1 of the following experimental groups (n = 40): traditional endodontic cavity and CEC. Teeth were subdivided according to instrumentation (n = 10) as follows: ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland), Reciproc (VDW GmbH, Munich, Germany), Reciproc Blue (VDW GmbH), and Hyflex EDM (Coltene/Whaledent, Altstätten, Switzerland). After canal obturation, teeth were restored using temporary material, conventional composite, regular bulk fill composite, or bulk fill flow combined with conventional composite. Before and after preparation and after obturation, the teeth were scanned using micro-computed tomographic imaging. Canal transportation (CT), the percentage of untouched canal surfaces (UCSs), voids in restoration (VRs), and residual filling material in the pulp chamber were evaluated. Finite element analysis, fracture resistance, and the failure pattern were recorded. The data were analyzed using analysis of variance and the Tukey and chi-square tests.
CECs had greater CT, percentage of filling material, and VRs compared with traditional endodontic cavities (P < .0001). The highest CT and UCSs were observed in CEC with ProTaper Universal. Bulk fill flow combined with conventional composite showed a lower percentage of VRs compared with other restorative materials (P < .05). Finite element analysis, fracture resistance, and failure pattern revealed similar behaviors in all groups (P > .05) .
CECs had a negative impact on root canal centralization, UCSs, cleaning of the pulp chamber, and percentage of VRs. Controlled memory instruments were the most adequate for the root canal preparation of CECs. The endodontic cavity did not influence the biomechanical behavior of restored teeth.
本研究旨在评估保守性根管腔（CEC）对使用不同成形系统和修复材料预备的牙齿的根管预备、修复和生物力学行为的影响。
将 90 颗上颌前磨牙根据形态学进行匹配，并随机分为对照组（n=10）或以下 1 个实验组（n=40）：传统根管腔和 CEC。根据器械（n=10）将牙齿进一步细分如下：ProTaper Universal（登士柏麦尔乐，Ballaigues，瑞士）、Reciproc（VDW GmbH，慕尼黑，德国）、Reciproc Blue（VDW GmbH）和 Hyflex EDM（科尔泰尼/惠尔登，阿尔特施塔特，瑞士）。根管充填后，用临时材料、常规复合树脂、常规块状填充复合树脂或块状填充流动复合树脂联合常规复合树脂进行修复。预备前后和根管充填后，用微计算机断层扫描成像对牙齿进行扫描。评估根管偏移（CT）、未触及根管表面百分比（UCSs）、修复体中的空隙（VRs）和牙髓腔中残留的填充物。记录有限元分析、抗折强度和失效模式。使用方差分析和 Tukey 和卡方检验对数据进行分析。
CEC 的 CT、填充材料百分比和 VRs 均大于传统根管腔（P<.0001）。ProTaper Universal 制备的 CEC 具有最大的 CT 和 UCSs。与其他修复材料相比，块状填充流动复合树脂联合常规复合树脂的 VRs 百分比更低（P<.05）。有限元分析、抗折强度和失效模式表明所有组的行为相似（P>.05）。
CEC 对根管中心化、UCSs、牙髓腔清洁和 VRs 百分比有负面影响。有控制记忆的器械是制备 CEC 最适宜的根管预备器械。根管腔不影响修复牙的生物力学行为。
