Bioactive Bilayer Glass Coating on Porous Titanium Substrates with Enhanced Biofunctional and Tribomechanical Behavior

Ana M Beltrán,Ana Alcudia,Belén Begines,Paloma Trueba,Yadir Torres,Flora Borie,José A Rodriguez-Ortiz

doi:10.3390/coatings12020245

Abstract

The use of porous titanium samples fabricated by space-holder powder metallurgy with bioactive coatings has already been reported to prevent resorption of the bone surrounding the implant and improve osseointegration, respectively. However, the presence of pores as well as the poor adherence and the brittle behavior inherent to glassy coatings affect the service behavior of implants fabricated from these samples. Therefore, they need to be optimized. In this work, 50 vol.% of porosity titanium substrates were manufactured with different pore range size (100–200 and 355–500 µm) spacer particles and coated with a bilayer of bioactive glasses (45S5/1393). The effect of the pores on the tribomechanical properties and infiltration of the bioactive glass 1393 along with the bioactivity of the bioactive glass 45S5 were evaluated by instrumented micro-indentation and scratch tests and the formation of hydroxyapatite in simulated body fluid. The results obtained were very promising as potential implants for the replacement of small tumors in cortical bone tissues, mainly due to the smaller pores that present an improved biomechanical and biofunctional balance.

Highlights

Academic Editor: Sara FerrarisThe area of implant manufacture is attracting growing attention due to the result of a longer life expectancy (i.e., Spain and Italy had the highest life expectancy among EU countries, reaching over 83 years in 2018)
It is well known that implants for young people are subject to a higher mechanical load for longer periods of time, so the development of new strategies and methodologies to improve knowledge about these devices plays a crucial role in the field
We have reported previous studies focused on a singular approach that includes the use of controlled porous implants covered with a bilayer coating; the inner layer that is in contact with the titanium substrate that has a greater infiltration capacity, a closer dilatation coefficient compared to Ti, and significant adherence to the pores (BG 1393); and the outer layer (BG 45S5), which exhibits better bioactivity with physiological fluids

Summary

Introduction

Academic Editor: Sara FerrarisThe area of implant manufacture is attracting growing attention due to the result of a longer life expectancy (i.e., Spain and Italy had the highest life expectancy among EU countries, reaching over 83 years in 2018). It is well known that implants for young people are subject to a higher mechanical load for longer periods of time, so the development of new strategies and methodologies to improve knowledge about these devices plays a crucial role in the field. In this context, more specialized and multidisciplinary research is needed to implement prototypes and in vivo performance of small implantable devices to replace damaged bone tissues in small bone-localized tumors [1,2]. The use of porous substrates could implement stress-shielding behavior At this point, the space-holder manufacturing technique described

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