Effect of simulated toothbrushing and repolishing on a monochromatic resin composite gloss, roughness, color change and fluorescence after staining

• Grant number: 25/09765-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2025
• End date: September 30, 2026
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Rubens Nisie Tango
• Grantee: Giovanna Honorato Vieira
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

Due to advances in materials and adhesive techniques, direct restorations with composite resin have become the first choice for restorative procedures, offering less invasive approaches. The emergence of monochromatic resins has made it possible to reduce clinical time compared to conventional resins, allowing the use of a single shade for dental structures of different colors - a phenomenon known as the "chameleon effect." This study aims to evaluate the effects of simulated brushing and repolishing on the gloss, surface roughness, color change, and fluorescence of conventional and monochromatic composite resins after exposure to staining solutions. A total of 80 specimens (8.00 mm in diameter × 2.00 mm thick), 40 of each material (Vittra APS Unique and Vittra APS), will be fabricated, light-cured, polished, and subjected to gloss, roughness, color, and fluorescence evaluations. The specimens will be divided according to the type of resin into 2 groups, followed by the random creation of 4 subgroups (n=10) within each group: artificial saliva (control group), coffee, wine, and Coca-Cola¿. Gloss, roughness, color change, and fluorescence analyses will be repeated after 60 and 120 hours of staining. For simulated brushing, a brushing machine and a low-abrasivity dentifrice diluted in distilled water (1:4) will be used. Repolishing will be performed using Diamond Flex felt discs (FGM) with Diamond Excel Ultrafine polishing paste, followed by Diamond felt discs (8/12 mm - FGM), both mounted on a contra-angle electric handpiece (Trihawk, Trihawk Brasil) at a speed of 15,000 rpm, with light pressure, for 30 seconds at each stage. Data obtained will be evaluated using descriptive and inferential statistics, considering a significance level of 5%.