Evaluation of methods of staining removal of a 3D-printed resin for denture teeth

• Grant number: 24/18775-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: January 31, 2026
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Ana Carolina Pero
• Grantee: Giovanna Bueno de Souza
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Obtaining prosthetic parts through digital flows represents an innovation in dentistry. Among the digital flows for manufacturing complete dentures, the printing of artificial teeth with specific light-cured resins can be considered. However, these materials are subject to staining when exposed to coloring beverages, and the literature has not yet established a stain removal protocol that is effective in maintaining their aesthetics and surface properties. The objective of this study will be to evaluate methods for removing stains from a resin for 3D printing of artificial teeth. The color properties and surface roughness of the resin for artificial teeth pRizma 3D Bio Crown, color A1 will be evaluated. Discs (10 x 1.2 mm, n=50) will be printed on the Flashforge Foto 6.0 LCD printer at 90º and subjected to staining in instant coffee for three days, simulating 1 year of consumption. Subsequently, they will be randomly subjected to the treatments: 1-Corega Tabs, 2-0.5% sodium hypochlorite, 3- conventional polishing with brush and pumice stone 90 s at 1500 rpm + felt wheels and universal paste for 15 s at 3000 rpm, 4- polishing with 3-tip kit (1 min/tip at 5000 rpm) and 5-distilled water (control). Specimens from groups 1, 2 and 5 will be immersed in the respective solutions for 04 cycles of 8 hours to simulate weekly cleaning for 01 month. Groups 3 and 4 will undergo 04 weekly polishing cycles. Color data (L, a, b) will be obtained on a spectrophotometer and roughness Ra (µm) on a digital perfilometer, in the periods: T0, before immersion in coffee (baseline), T1, after the simulated period of 01 year of coffee consumption, and T2, after the different stain removal treatments. The color comparison will be given by the value of ¿E00, obtained using the CIEDE2000 formula, and the roughness will be compared based on the Ra averages obtained under the proposed experimental conditions. For both dependent variables, the stain removal protocols, at 05 levels, and the evaluation periods, at 03 levels, will be considered variation factors. A qualitative analysis of the surface topography of the specimens will also be carried out, for all experimental conditions, through the analysis of images obtained using a scanning electron microscope (SEM). The quantitative data will be subjected to appropriate statistical tests with ¿=0.05.