Effect of different organic solvents on surface roughness and adhesion of microorganisms on PMMA for CAD/CAM, polished with diamond-coated silicone tips

• Grant number: 23/04593-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2023
• End date: May 31, 2024
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Aldiéris Alves Pesqueira
• Grantee: Amanda Martinelli Moretti
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

Despite all the significant advances in contemporary restorative materials, these materials suffer from degradation, which can compromise their integrity and durability. Ethanol and methyl ethyl ketone (MEK) are two organic solvents, found respectively in beverages and foods are considered food simulating solutions and have been used to test the durability of different restorative materials, simulating the buccal chemical environment. In view of the above, the aim of the present study will be to characterize the surface and analyze the microbiological characteristics of of reticulated PMMA block for manufacturing by CAD/CAM system, polished with silicone tips coated with diamond or photopolymerizable surface sealant and immersed in organic solvents (distilled water, 70% ethanol and methyl ethyl ketone). The study will have four factors under analysis: (1) prefabricated polymer block (PMMA) for the CAD/CAM system; (2) Surface treatments : POG: silicone tips coated with diamond - OptraGloss/Ivoclar or SP: photopolymerizable surface sealant - Palaseal/Kulzer; (3) Immersion in 03 organic solvents simulating food (I): distilled water (IA), ethanol absolute - Merck (IE) and methyl ethyl ketone - Sigma-Aldrich (IMEK); (4) (4) analysis times at 4 levels (TB - after 24 h of surface treatment, stored in dry conditions at 37°C (baseline); T1 - after 24 h of immersion (IA, IE and IMEK) at 37° and T2 - after 7 days of immersion (IA, IE and IMEK) at 37°. Three response variables will be considered: (1) characterize the surface through the surface roughness (Ra); (2) Microbiological analysis of mixed biofilm of S. mutans and C. albicans by means of (2.1) Quantification of cultivable cells (CFUs) and (2.2) analysis of the structure of biofilms by scanning electron microscopy (SEM). The quantitative data obtained in each analysis will be submitted to the normality test and later to the most appropriate statistical test, with a significance level of 5%. Qualitative data will visualize the biofilm structure formed, comparing between the different proposed groups.