Numerical modeling of the fracture process in a three-unit all-ceramic fixed partial denture

Objectives The main objectives were to examine the fracture mechanism and process of a ceramic fixed partial denture (FPD) framework under simulated mechanical loading using a recently developed numerical modeling code, the R-T2D code, and also to evaluate the suitability of R-T2D code as a tool for this purpose. Methods Using the recently developed R-T2D code the fracture mechanism and process of a 3 U yttria–tetragonal zirconia polycrystal ceramic (Y–TZP) FPD framework was simulated under static loading. In addition, the fracture pattern obtained using the numerical simulation was compared with the fracture pattern obtained in a previous laboratory test. Results The result revealed that the framework fracture pattern obtained using the numerical simulation agreed with that observed in a previous laboratory test. Quasi-photoelastic stress fringe pattern and acoustic emission showed that the fracture mechanism was tensile failure and that the crack started at the lower boundary of the framework. The fracture process could be followed both in step-by-step and step-in-step. Significance Based on the findings in the current study, the R-T2D code seems suitable for use as a complement to other tests and clinical observations in studying stress distribution, fracture mechanism and fracture processes in ceramic FPD frameworks.