Department of Conservative Dentistry and Endodontics, Maulana Azad Institute of Dental Sciences, MAMC Complex, Bahadur Shah Zafar Marg, New Delhi, 110002, India.
Clin Oral Investig. 2021 Dec;25(12):6671-6679. doi: 10.1007/s00784-021-03953-1. Epub 2021 Apr 26.
This study aimed to assess the effects of revascularisation and apexification procedures on biomechanical behaviour of immature teeth using 3-dimensional finite element analysis (3D FEA).
Five 3D FEA permanent maxillary incisor models were developed from CBCT scans and available literature data: Model MT: Mature tooth, Model IT: Immature tooth (Cvek's stage 3), Model AT: Apexified tooth-mineral trioxide aggregate (MTA) apexification, Model RTB: Revascularised tooth with blood, and Model RTS: Revascularised tooth with supplementary scaffold. Using FEA, a masticatory load of 240N at 120° was simulated, and the Von Mises and maximum principal stresses within the models were evaluated. Failure index (FI) and weakening% were also calculated for each model.
On dentinal stress analysis, model MT (96.16MPa) and IT (158.38MPa) had lowest and highest stress values, respectively. Among the experimental groups, model RTS (131.12MPa) had lower stresses than AT (136.33MPa) and RTB (133.7MPa), with no significant difference among the three. Peak dentinal stresses in all the models were observed in the cervical third of the root and near the apical opening in model IT. The extent of high dentinal stress area in model RTB and RTS was lesser than that of AT. The FI and weakening% values were highest for model AT followed by RTB and RTS, among the experimental groups. However, all these treatments strengthened an immature tooth by more than 20%.
AT, RTB, and RTS treatments lowered the stress values and risk of fracture in immature teeth with no significant difference among the three groups.
Stress distribution evaluation following revascularisation/apexification was essential, with potential to influence clinical decision-making. MTA apexification and revascularisation with blood clot/supplementary scaffold lowered the stresses in immature teeth, with no significant difference among the three.
本研究旨在通过三维有限元分析（3D FEA）评估再血管化和根尖诱导成形术对未成熟牙生物力学行为的影响。
根据 CBCT 扫描和现有文献资料，建立了五组 3D FEA 上颌恒切牙模型：模型 MT：成熟牙；模型 IT：未成熟牙（Cvek 3 期）；模型 AT：根尖诱导成形术-矿物三氧化物聚合体（MTA）；模型 RTB：血运重建牙；模型 RTS：血运重建牙+补充支架。通过 FEA 模拟 120°咀嚼负荷 240N，评估模型内的 Von Mises 和最大主应力。还计算了每个模型的失效指数（FI）和弱化率（%）。
在牙本质应力分析中，模型 MT（96.16MPa）和 IT（158.38MPa）的应力值最低和最高。在实验组中，模型 RTS（131.12MPa）的应力值低于 AT（136.33MPa）和 RTB（133.7MPa），但三者之间无显著差异。所有模型的牙本质最大峰值均出现在根的颈三分之一处和 IT 模型根尖开口附近。RTB 和 RTS 模型中的高牙本质应力区域的范围小于 AT 模型。在实验组中，FI 和弱化率%值最高的是 AT，其次是 RTB 和 RTS。然而，所有这些治疗方法都使未成熟牙的强度提高了 20%以上。
AT、RTB 和 RTS 治疗方法降低了未成熟牙的应力值和骨折风险，三组之间无显著差异。
再血管化/根尖诱导成形术后的应力分布评估至关重要，可能会影响临床决策。MTA 根尖诱导成形术和血运重建术+补充支架降低了未成熟牙的应力，三组之间无显著差异。
