Chemical and mechanical effects of the incorporation of Bombyx mori silk nanoparticles in thermopolymerizable acrylic resin

• Grant number: 22/15651-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2023
• End date: May 31, 2024
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Rodrigo Galo
• Grantee: Igor Majuste Alves Ambrosio
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The ideal material for the base of dental prostheses must be biocompatible with oral tissues, present excellent aesthetics, resistance to flexion and hardness, resistance to impact, and good mechanical properties. Thus, polymethylmethacrylate (PMMA) is the polymer most used in the manufacture of prosthetic bases due to its ease of processing and repair capacity, lightness, low cost, low water sorption and solubility, in addition to presenting good aesthetic properties. Silk fibroin (FS) is a biomaterial produced by the silkworm (Bombyx mori) and has been used by the textile industry for many years. It is a polymer widely used in research in biomedical and biotechnological applications, for presenting high resistance and mechanical toughness, high biocompatibility, processing flexibility, resistance to chemical substances and microorganisms, in addition to the ability to resist enzymatic breakdown and high resistance to moisture. This biomaterial has been applied in surgical sutures, scaffolds for tissue regeneration in cell culture substrates and drug delivery substrates. Therefore, the objective of this study will be to incorporate FS into thermopolymerizable acrylic resin in order to verify the association with possible chemical and mechanical effects. Thirty rectangular specimens, with dimensions of 64.0 mm in length, 10.0 mm in width and 3.0 mm in thickness will be prepared and divided into three groups (N=30): G1 (control) - thermopolymerizable PMMA without reinforcement; G2: thermopolymerizable PMMA with addition of 0.5% silk nanoparticles; G3: Thermopolymerizable PMMA with the addition of 1% silk nanoparticles. The groups will be submitted to tests of surface roughness, flexural strength and microhardness.