Abstract
Implant systems come with the aesthetic development, offering ceramic components for implant prostheses, whites, who favour the attainment of the desired pink aesthetics, in detriment of metal components, which can be viewed by transparency in patients with thin gingival tissue. Prosthetic abutments and ceramic copings have been obtained by means of CAD/CAM technology allowing to quickly obtain parts with good adaptation that will encourage masquerading dento-gingival avoiding the conventional processes of casting and machining of metallic alloys. The use of ceramics with high content, high density crystalline, oxide-based zirconia (ZrO2) have been proposed for obtaining structures for CAD/CAM, in view of their biocompatibility, high hardness and wear resistance, flexural strength and fracture toughness, associated with the color, favoring the aesthetics. Clinical longevity of ceramic restorations have intimate relationship with their esthetic, mechanical and adhesive properties. The zirconia, although satisfactory in biomechanical and aesthetic issues, presents problems concerning the accession, which has been a topic of great interest in recent years, since the ideal methodology to promote a stable and durable bonding between zirconia structures remains unknown. It is of the utmost importance that mechanisms of Union-based zirconia systems are improved, considering that a satisfactory bonding will promote retention, prevent microleakage and, in long term, you can increase the resistance to fracture and fatigue in oral environment. On the facts, is believed to be of great value to the dentistry analyze and compare the effectiveness of different methods for surface treatment on adhesion of zirconia blocks obtained by CAD/CAM, to the resin cement. Still, evaluate the bond strength after Thermo-mechanical cycling between crowns "metal free" with zirconia copings and customized abutments of the same material, obtained also by the CAD/CAM process, characterizing the interfaces and surfaces of materials against the different proposed treatments. Samples obtained by CAD/CAM will be subjected to treatment with hydrofluoric acid 40%, with nanoparticles film with ZiO2 and SiO2-ZrO2, and silicatization. Surfaces, pre-and post-treatment, will be featured in laser confocal microscope, in electron microscope (EDS and XRD); wettability, surface free energy and dynamic elastic modulus will be measured. Also will be measured the adhesive resistance to resin cement. Then, CAD/CAM crowns and zirconia abutments will be subjected to use simulation test and to accelerated fatigue under thermomechanical cycling. (AU)