[Stress analysis of the post and core system under loading].
OBJECTIVE
To analyze the stress of the post and core system by using finite element analysis and study the influence of the "crown materials" on the analytic results.


METHODS
Three groups of 3D finite element models of maxillary incisors were established according to the fabricating standard of the post and core system by using I-DEAS finite element analysis software. Group A was consisted of the cast metal post and core, the tooth structure after preparation and the periodontal structure. Group B was composed of the PFM, the cast metal post and core, the tooth structure after preparation and the periodontal structure. Group C was composed of the resin crown, the cast metal post and core, the tooth structure after preparation and the periodontal structure. The three groups were loaded and analyzed under the same loading according to the mean value of the bite force of incisors.


RESULTS
(1)The maximum stress of dentin in group A was twice higher than that in group B. The maximum primary stress, minimum primary stress and maximum shear stress of group A were respectively 236.35, 228.83 and 218.05 percent of those in group B. The difference of maximum stress values of group B and group C was neglectable. (2) The maximum stress distribution of dentin in group A and group B was quite different (the stress was concentrated in labial and lingual side of the cervical dentin in group A, otherwise in group B it was concentrated in the area around the alveolar and the labial and lingual side of the dentin which was opposite to the tip of the cast metal post and core). The maximum stress distribution of dentin in group A and group B was almost the same.


CONCLUSIONS
Different materials of the crown did not influence the result of 3D finite element stress analysis of the post and core system.
Weng
Wei-min
WM
Department of Prosthodontics, School of Stomatology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Key Laboratory of Stomatology, Shanghai Research Institute of Stomatology, Shanghai 200011, China.
Zhu
Zi-yuan
ZY
Zhang
Bao-wei
BW
Weng
De-xing
DX
D001732:Bite Force; D003799:Dental Stress Analysis; D003804:Dentin; D020342:Finite Element Analysis; D006801:Humans; D011176:Post and Core Technique; D019228:Tooth Crown