Premium
Correlation between cuspal inclination and tooth cracked syndrome: a three‐dimensional reconstruction measurement and finite element analysis
Author(s) -
Qian Yunzhu,
Zhou Xuefeng,
Yang Jianxin
Publication year - 2013
Publication title -
dental traumatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 81
eISSN - 1600-9657
pISSN - 1600-4469
DOI - 10.1111/j.1600-9657.2012.01160.x
Subject(s) - molar , ultimate tensile strength , dentistry , orthodontics , finite element method , stress (linguistics) , materials science , medicine , composite material , structural engineering , engineering , linguistics , philosophy
Background/Aim This paper explored the correlation between cuspal inclination and tooth cracked syndrome by measuring and reconstructing the cuspal inclinations of cracked maxillary first molars through three‐dimensional (3 D ) finite element analysis (FEA). Material and methods The cuspal inclinations of 11 maxillary left first molars with cracked tooth syndrome and 22 intact controls were measured by 3 D reconstruction. The mean values of each group were used to construct two 3 D finite element models of maxillary first molar for comparing stress distribution under the loads of 200 N at 0°, 45°, and 90°, respectively, to the tooth axis. Results There was statistically significant difference in the cuspal inclination between the incompletely fractured group and the intact control group ( P < 0.001), which was 5.5–6.7 degrees steeper. The model from the mean cuspal inclinations of the incompletely fractured molars showed the maximum tensile stress of 5.83, 10.87, and 25.32 M Pa, respectively, in comparison with 5.40, 8.49, and 22.76 M Pa for the model of the control group. Besides, the tensile stress was mainly at the center groove and cervical region of the molar model. Conclusions Steeper cuspal inclinations resulted in an increment in tensile stress that was mainly at the center groove and cervical region of the molar model under equivalent loads. Higher unfavorable tensile stress was generated with the increasing horizontal component load on the cuspal incline. This indicates an effective reduction of cuspal inclination to the compromised teeth for dentists.