EVALUATION OF THE REMINERALIZING AND ANTIMICROBIAL EFFECTS OF BIOACTIVE EXPERIMENTAL RESIN INFILTRANTS AFTER AGING

• Grant number: 24/19688-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2025
• End date: December 31, 2025
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Giselle Maria Marchi
• Grantee: Giovanna Freire Borges
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

The present study aims to evaluate, in vitro, the remineralizing and antimicrobial effects of experimental resin infiltrants incorporated with the monomer dimethylaminohexadecyl methacrylate (DMAHDM) and inorganic amorphous calcium phosphate nanoparticles (NACP 1.5%) after the aging of treated carious lesions. Six experimental groups will be tested: (1) experimental base infiltrant (IB), (2) base infiltrant with 0.75% (m/m) DMAHDM (DM0.75), (3) base infiltrant with 1.5% DMAHDM (DM1.5), (4) base infiltrant with 1.5% (m/m) NACP (NACP), (5) infiltrant containing 0.75% (m/m) DMAHDM associated with 1.5% NACP (DM0.75_NACP) and (6) infiltrant containing 1.5% (m/m) DMAHDM associated with 1.5% NACP (DM1.5_NACP). Additionally, a commercial control group (IC), represented by Icon® (DMG, Hamburg, Germany), will be included. The methodology will be divided into two stages. In the first stage, early carious lesions will be chemically induced in bovine enamel specimens (n=70), followed by treatment with the application of infiltrants and exposure to a cariogenic challenge for 48 hours with Streptococcus mutans. In the second stage, the samples will undergo simulated aging, followed by a new 48-hour cariogenic challenge. The properties to be evaluated include Knoop surface microhardness (n=10), analyzed at three experimental time points: sound enamel, after treatment with infiltrants, and after aging. Additionally, the antibacterial potential will be assessed using the MTT assay (n=10) before and after thermal aging. Finally, the surface morphology of the samples will be analyzed using Scanning Electron Microscopy (SEM) (n=3). The data will be tested for normality and homoscedasticity and then subjected to appropriate statistical analyses (significance level of 5%). The expected results should confirm the durability and efficacy of bioactive infiltrants in inhibiting the progression of early carious lesions, even after aging, providing an effective and long-lasting therapeutic approach.