Stress analysis of mandibular first molars repaired in two ways
10.3760/cma.j.cn431274-20230801-00075
- VernacularTitle:两种方式修复下颌第一磨牙应力分析
- Author:
Tao LIU
1
;
Qiguo RONG
;
Jianzhang LIU
Author Information
1. 济宁医学院附属医院口腔科，济宁 272100
- Keywords:
Molar;
Endocrown;
Crowns;
Finite element analysis;
Post and core technique
- From:
Journal of Chinese Physician
2024;26(11):1657-1663
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To establish a finite element model of the mandibular first molar with three wall defects, simulate the repair effect of fiber post porcelain crown and modified inlay, and analyze the effect of crown defect location on abutment stress.Methods:One intact mandibular first molar was extracted due to periodontal disease. Conical beam computed tomography (CBCT) was used to obtain the data, Mimics, Geomagic, and Ansys software were used to construct the mandibular first molar model, and 8 groups of models (groups A, B, C, D of fiber post all-porcelain crown and groups E, F, G, and H of modified onlays) were established according to different locations and repair methods of the three wall defects. Four forces (F1, F2, F3 and F4) were selected to compare the maximum Von Mises stress and its distribution.Results:The extreme values of dentin Von Mises stress were 19.334 9-19.907 1 MPa(F1), 8.295 47-8.466 08 MPa(F2), 19.433 5-19.441 4 MPa(F3) for fiber post all-porcelain crown restoration (group A, B, C and D models), respectively. 36.109 3-36.199 8 MPa(F4); The maximum values of Von Mises stress were 19.493-19.864 8 MPa(F1) in modified high inputate restoration (E, F, G, H). 9.077 35-9.317 12 MPa(F2), 22.770 6-23.541 2 MPa(F3), 35.724 2-35.989 7 MPa(F4). There was little change among the models. The extreme value of dentin stress increased with the increase of loading Angle. Under the same defect mode, the extreme value of dentin stress in groups A, B, C and D was less than that in groups E, F, G and H at F2 and F3. At F1 and F4, the extreme values of dentin stress in the eight groups were similar, but the dentin stress concentration area in groups A, B, C and D was located on the tooth surface, and the stress concentration area appeared in the pulp chamber in groups E, F, G and H.Conclusions:The position of the defect has no significant effect on the repairing effect of the modified inlay and the fiber post porcelain crown. The fiber post porcelain crown is more beneficial to disperse the dentin stress.
