Beta titanium alloys, the third generation of implant dentistry biomaterials: analysis of the physical, chemical, mechanical, and biological properties of Ti-35Nb-7Zr-5Ta and Ti-6Al-4V discs obtained by machining and additive manufacturing

Author(s)

Juliana Dias Corpa Tardelli

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Ribeirão Preto (PCARP/BC)
• Defense date: 2022-06-14

Examining board members

Andréa Candido dos Reis; Márcio Mateus Beloti; Jamil Awad Shibli

• Advisor: Andréa Candido dos Reis

Abstract

Knowledge of the properties of materials used for dental implants is essential and the first step before performing in vivo studies. The aim of the present study was to compare in vitro the physical, chemical, mechanical, and biological properties between disks of Ti-6Al-4V and Ti-35Nb-7Zr-5Ta (TNZT) obtained by Machining and Selective Laser Melting (SLM). For this purpose, 40 discs (Ø 5.0 mm x 1 mm thick) were used, divided into 4 groups (n=10) according to alloy and manufacturing technique. The disks were analyzed by scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), x-ray diffraction (XRD), wettability, surface free energy, roughness by confocal laser microscopy, and atomic force (AFM), Vickers microhardness and colony-forming units (CFU). Two-way ANOVA was applied to all quantitative data with a significance level of 5%. The difference in the manufacturing technique was observed by SEM, which demonstrated a melted surface for Machined and partially melted for SLM; the chemical composition of the alloys evaluated by EDS was compatible with the concentrations expected for each element in the literature; for XRD the processing route interfered in the phase for TNZT; for wettability and surface free energy the alloy was statistically significant (p<0.041); for roughness, the manufacturing technique was statistically significant (p<0.001) with higher averages for the groups obtained by SLM, corroborating the qualitative analysis by AFM; for Vickers microhardness the manufacturing technique (p=0.018) and alloy (p<001) were statistically significant; and for UFC, both the manufacturing technique and the alloy had no significant influence. It was concluded that the morphology observed by SEM is consistent with the Manufacturing Technique used, being rougher for the SLM; The Manufacturing Techniques did not interfere with the specific concentrations of each element of the evaluated alloys; The processing route is the main reason for the phase variation present in the TNZT groups; The wettability of SLM surfaces is similar to Machined; TNZT alloy has a higher surface free energy and wettability than Ti-6Al-4V; The surfaces obtained by SLM are rougher, in addition to TNZT being rougher regardless of the technique; The microhardness of an implant can be influenced by the alloy and manufacturing technique; The polishing to make the peaks of the SLM surfaces rounded added to the bacterial adaptation can explain the non-difference in the CFU results. (AU)

• FAPESP's process: 20/05272-2 - Beta-titanium alloys, the third generation of biomaterials for implantology: comparative analysis of physicochemical and mechanical properties between Ti-13Nb-13Zr and Ti-6Al-4V
• Grantee: Juliana Dias Corpa Tardelli
• Support Opportunities: Scholarships in Brazil - Master