Structural and mechanical behavior of ceramics with resin matrix for CAD/CAM system, subjected to mechanical polishing and surface sealant, whether or not associated with the application of low temperature plasma, after aging

Abstract

The present study will have as objective to evaluate the structural and mechanical characteristics of 03 resin-matrix ceramics for CAD/CAM, a resin nanoceramics (Cerasmart - GC), a glass ceramic in a resin interpenetrating matrix (VITA Enamic - VITA) and other zirconia-silica ceramic in a resin interpenetrating matrix (Shofu Block HC - SHOFU), after different polishing protocols (Ceramisté mechanical polishing kit (Shofu) or light curing surface sealant (Palaseal - kulzer) associated or not with PECVD film deposition (plasma-enhanced chemical vapor deposition), after different in vitro aging procedures (T-Thermocycling and EC-Erosive Challenge). 236 specimens of each ceramic will be made, being made two different sizes to fit in their respective analyses. The specimens will be divided into groups according to the surface treatment and aging they will undergo. The polishes performed will be: 1) Mechanical Polishing (MP) - that the mechanical polishing will be carried out with the Ceramisté kit (SHOFU, Kyoto, Japan); 2) Palaseal light curing surface sealant (SP) - a thin layer of Palaseal sealant will be applied (Heraeus Kulzer); 3) Mechanical Polishing (MP) + PECVD film deposition (Mp+ PECVD) - after MP, the surfaces of specimens in this group will be treated by deposition of PECVD films (plasma-enhanced chemical vapor deposition) and 4) Palaseal surface sealant (SP) + film deposition by PECVD (SP+ PECVD). The in vitro aging procedures will be: 1) Erosive Challenge (EC): immersion in HCl 5% (pH= 2,0) for 273 hours and 2) Thermocycling (T): to 30,000 thermocycling cycles varying the temperature between 5 and 55æC for 30 seconds. The response variables will be: 1) Structural analysis (surface roughness (Ra), contact angle and surface free energy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Atomic force microscopy (AFM)) and mechanical analysis (Vickers hardness (HV), Flexural strength (r) and modulus of elasticity (ME)). The data obtained will be submitted to the test of adherence to the normal curve, appropriate statistical test being applied to compare mean values of the samples.