Mechanical, physicochemical and microbiological properties of antimicrobial preheated composite resin for bonding orthodontic brackets

• Grant number: 24/00299-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2024
• End date: June 30, 2025
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Andréa Cândido dos Reis
• Grantee: Sofia Bignotto de Carvalho
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Preheated composite resin is a promising material for dentistry in the restorative and prosthetic areas, as it has favorable physical and mechanical characteristics for dental treatment. The use of nanostructured silver vanadate decorated with silver nanoparticles (²-AgVO3) is effective in preventing microorganisms associated with caries disease, which is commonly related to fixed orthodontic treatments. In the field of orthodontics, there is little discussion or research on the use of preheated antimicrobial composite resin for bonding orthodontic devices. This study aims to analyze the mechanical, physicochemical and microbiological properties of a preheated composite resin (Charisma Classic, Kulzer). The material will be preheated using a resin heater (Hotron, Biotron), at temperatures of 37°C and 68°C, and the specimens will be made from a Teflon matrix with dimensions of 12mm x 1mm. Surface roughness (n=10) will be assessed using 3D laser confocal microscopy and scanning electron microscopy (SEM) (n=1). Surface microhardness will be obtained using a microhardness meter (n=10).Shear strength will be assessed on a universal testing machine before and after thermocycling (n=10). The atomic composition of the surfaces will be observed by energy dispersive X-ray spectroscopy (EDS) (n=1). The degree of conversion will be analyzed using Fourier transform infrared spectroscopy (FTIR). Color change analysis will be carried out using a portable spectrophotometer (n=10). Antimicrobial activity will be assessed using the agar diffusion method (n=9). The results obtained will be subjected to parametric or non-parametric tests, depending on the distribution of the data (±=0.05).