Influence of the coefficient of thermal expansion on the stress distribution in ceramic veneers after thermal simulation

Abstract

The aim of the study was to evaluate the stress distribution in the ceramic veneers in a full prosthetic crown with different framework after the sintering and cooling cycle through the thermal analysis by three-dimensional finite element analysis. Using images from a computerized microtomography of a central incisor, an anterior crown was constructed. The models were composed of 2mm thickness ceramics (feldspathic ceramics) and 0.4mm thickness frameworks (zirconia, alumina, lithium-disilicate, or metal). Ansys Workbench finite element software was used for analysis and mesh generation through a 5% convergence. The thermal loading was performed in 2 stages simulating the heating and cooling of the ceramic veneer sintering cycle: stage 1 -403 to 750 degrees C; stage 2 -from 750 to 25 degrees C. The von Mises equivalent strain(σvM) was used for the quantitative and qualitative evaluation of the framework. The maximum (σmax) and minimum (σmin) stresses were used to evaluate the ceramic veneer and zirconia, alumina, and lithium-disilicate frameworks. The highest values of compressive stress (294,58 MPa) were found in the ceramic veneer in the models with alumina framework, followed by models with zirconia (253,65 MPa), palladium silver (239,74 MPa), and lithium disilicate (205,43MPa). The tensile stresses followed the same behavior presenting the highest values in the alumina prostheses (Al: 93,977

Stress distribution pattern on mandibular molar restored by occlusal veneer effect of veneer material and dental bonding surface

“…They concluded that, in regard to finite element analysis (or stress distributions), the information about reliability of thin CAD/CAM all ceramic occlusal veneer(s) and the influence of different preparation design on the performance of these restorations are still not enough. Stress distribution in the ceramic veneers in a full prosthetic crown, was evaluated by Carvalho et al [24] with different framework(s) by using 3D finite element analysis. The thermal study analysis was done for crowns after the sintering and cooling cycle through.…”

“…These stresses, their magnitude, distribution and orientation depend not only on the geometry of the structure but also on the loading configuration and the properties of the materials. [23,24] Finite Element Analysis is a significant research tool for biomechanical analyses in dental research. [25][26][27][28][29][30][31] The aim of this study was to assess the effect of occlusal veneer materials (lithium disilicate, zirconia, hybrid ceramic) and dental bonding surfaces (dentin, dentin with prepared cavity, and dentin with composite filling) on the stress distribution for a mandibular first molar restored with occlusal veneers, following different loading conditions.…”