Influence of the incorporation of functionalized niobium nanoparticles in experimental high-viscosity bulk-fill composite

• Grant number: 21/04561-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2021
• End date: April 30, 2022
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Marilia Mattar de Amoêdo Campos Velo
• Grantee: João Marco Alves
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

The use of high-viscosity bulk-fill resins in restorations under high occlusal load is controversial and, therefore, the improvement of their mechanical properties would be desirable and could improve the clinical performance of restorations with the bulk technique, expanding their indications. Thus, this in vitro study will evaluate the influence of the incorporation of nanoparticles of silanized niobium oxide (NbO2OH) on the mechanical properties of experimental high-viscosity bulk-fill resin by surface hardness, depth of cure, degree of conversion and flexural strength. Niobium nanoparticles (0.5%) will be weighed, added slowly into the experimental resin and homogenized for 1 minute. There will be a total of 3 groups: Group 1 (experimental high-viscosity bulk-fill resin, control); Group 2 (experimental high-viscosity bulk-fill resin modified by 0.5% functionalized NbO2OH) and Group 3 (bulk-fill resin Filtek One, 3M ESPE, positive control). The surface hardness will be conducted at the top of the surface and at the base (n = 6), with specimens made by a metallic matrix (4 × 4 mm), simulating the clinical condition of insertion in a single increment of the bulk resin. For the calculation of the depth of cure, a minimum of 80% of lower/upper microhardness will be established. The degree of conversion (n = 5) will be done using a Fourier-transformed infrared spectroscope (FTIR) with an attenuated total reflectance (ATR) accessory. Flexural strengths will be conducted using a Universal machine (Instron) (50N) in 10 specimens/group (size 8 × 2 × 2 mm). After verifying the normality of the data, two-way Analysis of Variance will be conducted, followed by the Tukey test (p <0.05). (AU)