Heat pressed ceramics crowns with and without zirconia framework - a biomechanical study

摘要

The patient demand for metal-free and tooth-colored restorations has driven substantial effort to increase the strength and reliability of dental ceramic systems. Heat pressed ceramic crowns with and without zirconia frameworks are restorations of choice from this point of view. Simulation of occlusal function during laboratory material's testing becomes essential in predicting long-term performance before clinical usage. The aim of the study was to assess the influence of chamfer preparation depth on failure risk of heat pressed ceramic crowns with and without zirconia framework by means of finite element analysis. 3D models of maxillary first premolars, prepared for MOD inlays with different depths of the chamfer preparations were generated (between 0.6 and 1.3 mm). The mesh structure of the solid 3D model was created using the computational simulation of Ansys finite element analysis software. An occlusal load of 100 N was conducted, and stresses occurring in the prepared teeth, pressed ceramic crowns, zirconia frameworks and pressed ceramic veneers were calculated. The highest stresses were registered in the pressed ceramics. The depth of the preparations had no significant influence on the stress values of the teeth and pressed ceramics for the studied cases, only for the zirconia framework. Stresses in teeth were not influenced by achieving of zirconia frameworks of pressed ceramic crowns.