Evaluation of mechanical, physical, optical and biological properties of permanent resins composites for 3D printing modified by boron nitride nanotubes

• Grant number: 23/13061-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2024
• End date: May 31, 2027
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Rafael Francisco Lia Mondelli
• Grantee: Fernanda Furuse Ventura dos Santos
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

3D printing technology, despite being considered established within Dentistry, still needs to be studied as the composition of 3D printed resins intended for the manufacture of permanent restorations and the performance of these materials in the face of challenges in the oral environment are not widely known. The addition of filler particles to resin-based materials aims to improve the durability of restorations. Boron nitride nanotubes have been gaining attention due to their excellent physicochemical properties, biocompatibility and bioactivity stimulating mineral precipitation. The objective of this study will be to evaluate the influence of the addition of different mass proportions of boron nitride nanotubes on the mechanical, physical, optical and biological properties of resins for 3D printing, intended for the manufacture of permanent restorations, post-polymerized in a post-cure chamber recommended by the manufacturer or with a dental light-curing unit. Two commercially available resins will be evaluated: Smart Print Bio Vitality B1 (Smart Dent, São Carlos, Brazil) and Prizma 3D Bio Crown A1 (Makertech Labs, Tatuí, Brazil) using a DLP printer (Flashforge Hunter, Flashforge, Jinhua, China). Boron nitride nanotubes (Multiwalled, powder, >90%, Sigma-Aldrich, MO, USA) will be added to them in proportions of 0wt%, 0.5wt% and 1wt%. The samples will be divided into groups according to the resin used, the concentration of nanoparticles incorporated and post-polymerization method. The modified nanoparticles and resins will be characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS). Part of the specimens will be post-polymerized using a post-cure chamber CiclOne (Creality, Shezhen, China) for 10 minutes and another part using a light-curing device Bluephase G4 (Ivoclar Vivadent, Liechtenstein) for 2 minutes. Manufacturing accuracy, flexural strength, elastic modulus, Knoop microhardness, surface roughness, color stability, translucency, loss of structure after erosive challenge by optical profilometry microscopy, biocompatibility, bacterial colony count and morphology and bioactivity by mineral deposition will be evaluated. Adopting an overall significance level of 5%, the results will be analyzed using analysis of variance tests, Weibull analysis and Tukey's multiple comparison tests.