Effect of the use of surface sealants associated with low temperature plasma on the optical characteristics of different rewin-matrix ceramics, submitted to different in vitro aging

Abstract

This project will have as general objective to to characterize the structure and optical 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 polishing kit (Shofu) or surface sealant (Palaseal - kulzer) associated or not with PECVD film deposition (plasma-enhanced chemical vapor deposition), after different in vitro aging procedures (T-Thermocycling or EC-Erosive Challenge and/or (I-immersion in acid/dye solutions (IDW - distilled water, , IBT - black tea and IRW-red wine). 240 specimens will be made it for each ceramic and 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 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+ PECDVD). The in vitro aging procedures will be: 1) Thermocycling (T): to 30,000 thermocycling cycles varying the temperature between 5 and 55oC for 30 seconds; 2) Erosive Challenge (EC): immersion in HCl 5% (pH= 2,0) for 273 hours and 3) Immersion in dye solution (I): immersion in three solutions - distilled water (IDW), black tea (IBT) and red wine (IRW) for 36 days. The response variables of the study will be: 1) structural analysis (surface roughness (Ra) and 2) color change (”E00, ”L, ”C, ”H), translucency (TP) and contrast (CR)). 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.