The effect of the application of different surface sealants on the surface degradation of PMMA polymer for CAD/CAM in thermocycling and erosion challenge

• Grant number: 21/01333-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2021
• Effective date (End): August 31, 2022
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Aldiéris Alves Pesqueira
• Grantee: Amanda Dias Castanheiro
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

The present study aims to evaluate the effect of the application of different surface sealants on the surface roughness and Knoop microhardness of PMMA polymer for CAD/CAM in thermocycling and erosion challenge. Ninety specimens of PMMA polymers for CAD/CAM in 10×10×3 (±0.5) mm dimensions will be distributed in four factors under analysis: (1) prefabricated polymer block (PMMA) for the CAD system/CAM; (2) surface treatments (PA: Astropol tips, SB: Biscover surface sealant and SP: Palaseal surface sealant); (3) Aging: (3.1) Temocycling (T): 5,000 cycles, from 5 to 55oC (T1); 10,000 cycles, from 5 to 55oC (T2); (3.2) Erosive Challenge (EC): immersion in 5% HCl (pH 2.0) for 45 hours (DE1) and 91 hours (DE2); (3.3) Control (C): specimens will not be obtained at aging (T or DE) and eliminated in controlled humidity throughout the experiment and (4) analysis times at 4 levels (T0 - after storage in distilled water for 24 hours , after T1, T2, DE1, DE2 and C. Two response variables will be evaluated: (1) surface roughness (Ra) and (2) Knoop microhardness (MK). The data obtained will be subjected to the adherence test of the normal curve, using an appropriate statistical test to compare the average values of the specimens.