Numerical fatigue analysis of premolars restored by CAD/CAM ceramic crowns

Publication date: Available online 10 April 2018
Source:Dental Materials
Author(s): Ehsan Homaei, Xiao-Zhuang Jin, Edmond Ho Nang Pow, Jukka Pekka Matinlinna, James Kit-Hon Tsoi, Khalil Farhangdoost
ObjectivesThe purpose of this study was to estimate the fatigue life of premolars restored with two dental ceramics, lithium disilicate (LD) and polymer infiltrated ceramic (PIC) using the numerical method and compare it with the published in vitro data.MethodsA premolar restored with full-coverage crown was digitized. The volumetric shape of tooth tissues and crowns were created in Mimics^®. They were transferred to IA-FEMesh for mesh generation and the model was analyzed with Abaqus. By combining the stress distribution results with fatigue stress–life (S–N) approach, the lifetime of restored premolars was predicted.ResultsThe predicted lifetime was 1,231,318 cycles for LD with fatigue load of 1400N, while the one for PIC was 475,063 cycles with the load of 870N. The peak value of maximum principal stress occurred at the contact area (LD: 172MPa and PIC: 96MPa) and central fossa (LD: 100MPa and PIC: 64MPa) for both ceramics which were the most seen failure areas in the experiment. In the adhesive layer, the maximum shear stress was observed at the shoulder area (LD: 53.6MPa and PIC: 29MPa).SignificanceThe fatigue life and failure modes of all-ceramic crown determined by the numerical method seem to correlate well with the previous experimental study.



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