Effect of cementation protocols on the fracture load of bilayer ceramic crowns manufactured by the Rapid Layer Technology.

To evaluate the fracture load of bilayer ceramic crowns manufactured by Rapid Layer Technology (RLT) after different cementation protocols of the veneering ceramic to the zirconia infrastructures. Sixty epoxy resin preparations simulating a molar tooth were obtained and 60 zirconia infrastructures and feldspathic crowns were manufactured by RLT and divided into 6 groups according to the cementation protocol at the interface to veneering ceramic (n=10): Ctr- control: conventional resin cement; Al- Al2O3 sandblasting 50µm + conventional resin cement; Al/MDP- Al2O3 sandblasting (50µm) + resin cement with MDP; Sil- silicatization 30µm + conventional resin cement; Gl/HF- glaze + hydrofluoridric acid (5%,60s) + silane + conventional resin cement; Gl- glazing as bonding agent. The feldspathic ceramic internal surface was etched with fluoridric acid (5%) + silane followed by cementation according to respective protocols.

Stress distribution around osseointegrated implants with different internal-cone connections: photoelastic and finite element analysis.

The goal of this study was to evaluate the distribution of stresses generated around implants with different internal-cone abutments by photoelastic (PA) and finite element analysis (FEA). For FEA, implant and abutments with different internal-cone connections (H- hexagonal and S- solid) were scanned, 3D meshes were modeled and objects were loaded with computer software. Trabecular and cortical bones and photoelastic resin blocks were simulated.