根管治疗后无金属翼（ferrule）核桩修复的前磨牙的有限元分析，采用一体式玻璃纤维桩和核，并结合不同的内肩固位形式系统。

Finite element analysis of endodontically treated premolars without ferrule restored with one-piece glass fiber post and core in combination with different inner shoulder retention form systems.

机构信息

The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, No. 117 North Street Nanjing Road, Shenyang, 110002, Liaoning, China.

出版信息

J Mech Behav Biomed Mater. 2023 Jul;143:105912. doi: 10.1016/j.jmbbm.2023.105912. Epub 2023 May 20.

DOI:10.1016/j.jmbbm.2023.105912

PMID:37270902

Abstract

OBJECTIVE

The current study was performed to explore the impact of post materials as well as the inner shoulder retention form (ISRF) design on the biomechanical behavior of endodontically treated premolars without ferrule restoration using a method of mathematical three-dimensional (3D) finite element analysis (FEA).

METHODS

Based on the tooth anatomy and our previous research, eight mandibular second premolar FEA models representing different restorative situations were built: teeth with (a) 2.0 mm height ferrule (DF), (b) no ferrule (NF), (c) 0.5 mm width and 0.5 mm depth ISRF (ISRFW0.5D0.5), (d) 0.5 mm width and 1.0 mm depth ISRF (ISRFW0.5D1.0), (e) 0.5 mm width and 1.5 mm depth ISRF (ISRFW0.5D1.5), (f) 1.0 mm width and 0.5 mm depth ISRF (ISRFW1.0D0.5), (g) 1.0 mm width and 1.0 mm depth ISRF (ISRFW1.0D1.0), (h) 1.0 mm width and 1.5 mm depth ISRF (ISRFW1.0D1.5). All groups were restored with prefabricated glass fiber post and resin composite core (PGF), one-piece glass fiber post-and-core (OGF) and cast Co-Cr alloy (Co-Cr) respectively, and the zirconia crown was restored. Load (180N) was subjected to the buccal cusp at 45° to the tooth's long axis. Stress pattern, maximum principal stress values (MPS), and maximum displacement values on root, post and core, cement layer were calculated for each model.

RESULTS

Stress distributions were similar while the values were different among groups. Regardless of restorative approaches, roots restored with PGF showed the highest MPS values, followed by OGF and Co-Cr groups. Regardless of post materials, NF groups resulted in the highest MPS values and maximum displacement values, while ISRF and DF groups exhibited similar results. Compared with PGF groups in association with ISRF, except for OGF with ISRFW0.5D0.5, the remaining OGF groups with ISRF and all Co-Cr groups in association with ISRF presented lower values than that of DF groups. And among different ISRF systems, roots restored with ISRFW1.0D1.0 presented the lowest stress (PGF: 32.96 MPa, OGF: 31.69 MPa, Co-Cr: 29.66 MPa).

CONCLUSIONS

For endodontically treated premolars without ferrule, restored with OGF in combination with ISRF preparation could effectively enhanced its load-bearing capacity. Furthermore, the ISRF with a depth and width of 1.0 mm is recommended.

摘要

目的

本研究旨在通过数学三维（3D）有限元分析（FEA）方法，探讨不同桩核材料及内肩保留形式（ISRF）设计对无金属全冠修复的根管治疗前磨牙生物力学性能的影响。

方法

基于牙齿解剖结构和我们之前的研究，建立了 8 个下颌第二前磨牙 FEA 模型，代表不同的修复情况：（a）2.0mm 高金属全冠（DF）；（b）无金属全冠（NF）；（c）0.5mm 宽×0.5mm 深 ISRF（ISRFW0.5D0.5）；（d）0.5mm 宽×1.0mm 深 ISRF（ISRFW0.5D1.0）；（e）0.5mm 宽×1.5mm 深 ISRF（ISRFW0.5D1.5）；（f）1.0mm 宽×0.5mm 深 ISRF（ISRFW1.0D0.5）；（g）1.0mm 宽×1.0mm 深 ISRF（ISRFW1.0D1.0）；（h）1.0mm 宽×1.5mm 深 ISRF（ISRFW1.0D1.5）。所有组均采用预制玻璃纤维桩和树脂核（PGF）、一体式玻璃纤维桩和核（OGF）以及铸造 Co-Cr 合金（Co-Cr）修复，并采用氧化锆全瓷冠修复。在牙长轴 45°方向向颊尖施加 180N 的载荷。计算每个模型的根、桩和核、粘结层的应力分布、最大主应力值（MPS）和最大位移值。

结果

各组的应力分布相似，但数值不同。无论修复方法如何，用 PGF 修复的根表现出最高的 MPS 值，其次是 OGF 和 Co-Cr 组。无论桩核材料如何，NF 组的 MPS 值和最大位移值最高，而 ISRF 和 DF 组的结果相似。与 PGF 联合 ISRF 相比，除了 OGF 联合 ISRFW0.5D0.5 组外，其余 OGF 联合 ISRF 组和所有 Co-Cr 联合 ISRF 组的 MPS 值均低于 DF 组。在不同的 ISRF 系统中，用 ISRFW1.0D1.0 修复的根的应力最低（PGF：32.96MPa，OGF：31.69MPa，Co-Cr：29.66MPa）。