Physicochemical properties, antimicrobial activity and cytotoxicity of multilayer silica nanoparticles with chlorhexidine incorporated into dental composites: in situ study

• Grant number: 23/11067-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2024
• End date: September 30, 2026
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Karina Cogo Müller
• Grantee: Larissa Pavanello Pandolfo
• Host Institution: Faculdade de Ciências Farmacêuticas (FCF). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The success of a dental treatment depends on several factors, such as the physicochemical properties of the materials used and the adherence of the buccal biofilm to their surfaces. Therefore, the aim of this study is to evaluate the physicochemical and antibacterial properties of experimental composites with multilayer silica nanoparticles loaded with chlorhexidine, synthesized by the layer-by-layer technique (CHX-SNPs) and inorganic particles. The experimental composites will be prepared with an organic matrix of BisGMA/TEGDMA (1:1), inorganic particles and CHX-SNPs, in the following concentrations: 0% (control group, GC); 20% CHX-SNPs (G1); 25, 45 or 65% barium glass (BG) + 30% colloidal silica (CS) and 20% CHX-SNPs (G2, G3 and G4, respectively); 25, 45 or 65% BG + 30% CS (G5, G6 and G7, respectively). The physicochemical and morphological properties will be evaluated through the degree of conversion (n = 5), post-gel volumetric shrinkage (n = 5), roughness (Ra, n = 6), flexural strength and flexural modulus (n = 10), Scanning Electron Microscopy (SEM) and Energy Dispersion X-Ray Spectroscopy (EDS) (n = 3). The antimicrobial activity will be evaluated in vitro (bacterial sensitivity test by agar diffusion technique (n = 5), and monospecies biofilm inhibition assay (n = 6), and in situ. Furthermore, the CHX release profile and cytotoxicity of the material in fibroblasts (ATCC L929) will also be investigated (n = 3). Data will be analyzed by ANOVA/Tukey or Kruskal-Wallis/Dunn and Student's "t" test or Mann-Whitney (a=5%) according to the conditions of normality and homoscedasticity. It is expected to obtain a material with antimicrobial activity and satisfactory physicochemical properties, with sustained release of CHX and biocompatible with oral cells.