Characterization of the biofilm formed on ceramics with resin-matrix ceramics for CAD/CAM, submitted to different polishing protocols associated or not with low temperature plasma deposition and different in vitro aging

• Grant number: 22/03791-8
• Support Opportunities: Scholarships in Brazil - Master
• Start date: July 01, 2022
• End date: May 31, 2024
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Aldiéris Alves Pesqueira
• Grantee: Kevin Henrique Cruz
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

Thus, the project will be divided into 2 studies that will have the general objective to characterize the structure and determine the amount of mixed biofilm formed on 03 ceramics with resin-matrix ceramics for CAD/CAM, 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 (STUDY 1: after T-Thermocycling or STUDY 2: after EC-Erosive Challenge). For each ceramic, there will be 96 square models with dimensions of 5 x 5 x 1.2 mm, divided into groups according to the surface treatment and aging they will undergo. The polishing performed will be: 1) Mechanical polishing (MP) - mechanical polishing will be performed with a 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 (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 55oC for 30 seconds. The response variables will be: 1) structural analysis (surface roughness (Ra) and microbiological analysis (2) colony forming units (CFU), 3) 3D analysis of the biofilm by confocal laser scanning microscopy (CLSM) and 4) analysis of the structure of biofilms by scanning electron microscopy (SEM). The quantitative data obtained will be submitted to the normal curve adherence test, and an appropriate statistical test will be applied to compare the average values of the samples. The results of the CLSM and SEM tests will be visually compared between the groups. (AU)