Effect of chairside polishing on monolithic ceramics for CAD/CAM system after immersion in acid/color solutions: surface characterization and optical properties

• Grant number: 19/12420-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2019
• End date: July 31, 2020
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Aldiéris Alves Pesqueira
• Grantee: Adriane Boaventura Chiorlin
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

During the milling, the CAD/CAM ceramic materials have some measure of roughness on their surface, caused by the abrasive diamonds particles from milling instruments. The increase in the surface roughness of the ceramic restorations changes its mechanical and aesthetic properties in a negative way. Nowadays, it is important to know if the chairside polishing kits results in a superior finishing and polishing or similar to the obtained with laboratory glaze, being this question of utmost importance. Owing to that, this study will evaluate the physical, chemical and mechanical characteristics of the CAD/CAM lithium disilicate, submitted to different polishing protocols and after different periods and acid/color immersion solutions. The study will have four factors under analysis: 1) Different polishing systems (G - Glaze, C - Ceramisté polishing kit (Shofu) and O - OptraFine polishing kit (Ivoclar); 2) Immersion solutions (AD - Distilled water, CP - Black tea and VT - Dry red wine); 3) Repolishing time (initial; after 54 hours; after 108 hours of immersion); 4) Analysis time in 3 levels (T0 - 0 hours; T1 - 54 hours; T2 - 108 hours). Seven variables responses will be considered: in the surface characterization: 1) Surface roughness (Ra); 2) Knoop test toughness; 3) Surface energy; 4) Scanning Electron Microscopy (SEM) associated with Energy Dispersive X-Ray Spectroscopy (EED); and in the optical properties: 5) Colors stability; 6) Translucency; 7) Luminance contrast. The data obtained will be submitted to the normal curve test, being applied the appropriate statistical test to compare the mean values of the specimens.