Effect of cigarette exposure on mechanical and surface properties of zirconia ceramics

• Grant number: 19/22010-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2020
• End date: January 31, 2021
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Flávio Henrique Baggio Aguiar
• Grantee: Eduarda Cauane Goulart de Faria
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

The study aims to investigate the effect of the cigarette on the mechanical and surface properties of the zirconia through a 3-point flexural strength test in a universal test machine, microhardness evaluation in a digital microdurometer, color analysis with the aid of spectrophotometer, roughness determination with a profilometer, and surface characterization by X-ray diffraction. Ten packages of Marlboro cigarette and 20 bars and 20 blocks of partially yttria-stabilized zirconia (Y-TZP) will be used, which will be randomly divided into two experimental groups: G1 (control) - not exposed to cigarette smoke and G2 - with exposure to cigarette smoke. The specimens will be sintered in an appropriate oven (Vita zyrcomat 6000 MS, Vita Zahnfabrik, Germany) according to the manufacturer's standards. On a surface of each specimen will be polished with silicon carbide sanding discs, followed by disks of feeling with diamond paste (AROTEC Ind. Com- São Paulo, Brazil) respectively in politriz (Arotec Ind. Com., São Paulo, Brazil ) under constant irrigation with water. Then all samples will be subjected to the heat treatment (heating rate 5 ° C / min, duration time: 2h at 1,200 ° C, cooling rate: 1 ° C / min) to eliminate any compressive stress generated by the polishing. The samples will be exposed to cigarette smoke and the smoke machine developed by the Department of Restorative Dentistry, School of Dentistry of Piracicaba - 2011 (registered under No. 01810012043 INPI - National Institute of Industrial Property), which allows the impregnation of pigments and substances contained in the cigarette, in restorative materials, in order to reproduce the conditions of the oral cavity of smokers in vitro. For statistical analysis, a completely randomized experimental design will be used, using one-way ANOVA. All data will be submitted to the IBM SPSSS program and if a difference between the groups be found it will be necessary to use a post hoc test, Tukey test with a significance level of 5%. (AU)