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In this study, the best equilibrium among adherence, micro-mechanical properties and coating bioactivity of bioactive glasses (45S5 and 1393) on porous titanium substrates has been explored and their potential uses for bone tissue implants. Porous titanium discs with different porosities (30 and 60 vol.%) and pore size distributions (100–200 and 355–500 µm) were utilized to rationalize their influence on both properties and performance. It was corroborated that porous samples produced a reduction in micro-hardness (~ 2000–4000 N/mm2) and the elastic modulus (~25–50 GPa), obtaining values closer to those of human bones, as well as induced a beneficial role to integrate the coatings. On one hand, bioglass 1393 presented greater capacity for pore infiltration while 45S5 was more bioactive. The results explained the better adherence and microhardness for bioglass 1393 and the significant formation of hydroxyapatite and calcium phosphates of bioglass 45S5, confirmed by 29Si MAS NMR. Ministerio de Ciencia e Innovación PID2019-109371GB-I00 Junta de Andalucía US-1259771

Stress-shielding and loosening compromise the success of dental implants under real-life service conditions. This work evaluates the mechanical behavior of superficially modified porous titanium dental implants fabricated by two different routes: conventional powder metallurgy and space-holder techniques. A novel, feasible and repetitive protocol of micro-milling of the implant thread (before sintering), as well as surface modification treatments (after sintering) are also implemented. The discussion is conducted in terms of the influence of porosity and surface roughness on the stiffness and yield strength of implants. The macro-pores concentrate stress locally, and, at the same time, they could act as a barrier to the propagation of micro-cracks. Higher rugosity was observed for virgin implants obtained with spacer particles. Concerning superficially modified implants, while bioglass 1393 was the most effective coating due to its greater infiltration and adhesion capacity, chemical etching could improve osteoblast adhesion because modifies the roughness of the implant surface. Premio Mensual Publicación Científica Destacada de la US. Escuela Politécnica Superior Ministry of Science and Innovation of Spain PID2019-109371GB-I00 Junta de Andalucía–FEDER (Spain) US-1259771

Porous titanium substrates coated by dripping-sedimentation technique with a novel bilayer of (45S5 / 1393) bioactive glasses are proposed to overcome some limitations of the use of titanium for implants, such as the stress shielding and the poor osseointegration. Composition, thickness, roughness and micromechanical behavior (P-h curves) of the coating and the influence of the porous titanium substrates have been characterized. Best results were found for the substrate with 30 vol.% of porosity and a range size of 355 ‒ 500 μm, since it enhanced the mechanical and biofunctional behavior, due to the good adhesion of the 1393 bioglass to the substrate and the greater bioactivity of the 45S5 bioglass, which would be in contact with the bone. M.E.C. (Spain) 2004/00001203 (RYC-2004-001497) Junta de Andalucía–FEDER (Spain) US-1259771

The chemical composition and surface topography of titanium implants are essential to improve implant osseointegration. The present work studies a non-invasive alternative of electrical impedance spectroscopy for the characterization of the macroporosity inherent to the manufacturing process and the effect of the surface treatment with femtosecond laser of titanium discs. Osteoblasts cell culture growths on the titanium surfaces of the laser-treated discs were also studied with this method. The measurements obtained showed that the femtosecond laser treatment of the samples and cell culture produced a significant increase (around 50%) in the absolute value of the electrical impedance module, which could be characterized in a wide range of frequencies (being more relevant at 500 MHz). Results have revealed the potential of this measurement technique, in terms of advantages, in comparison to tiresome and expensive techniques, allowing semi-quantitatively relating impedance measurements to porosity content, as well as detecting the effect of surface modification, generated by laser treatment and cell culture. Ministry of Science and Innovation of Spain grant PID2019-109371GB-I00 Junta de Andalucía–FEDER (Spain) Project US-1259771 Junta de Andalucía-Proyecto de Excelencia (Spain) P18-FR-2038

Ti implants are highly biocompatible and allow orderly bone growth but, unfortunately, in the first five years after implantation, 5–10% of them fail due to poor osseointegration and to the presence of bacterial infections in prosthesis. Silver nanoparticles have been described to damage bacterial cell via prolonged release of Ag+ ions as a mode of action when immobilized on a surface. In this work, two routes to synthetize silver nanoparticles have been proposed including, on the one hand, a NaBH4-reduction and, on the other hand, a citrate-reduction combined with a stabilized biodegradable polymer. The deposition of these nanomaterials on porous Ti substrates previously fabricated using the space-holder technique (40 vol% and two size distributions, 100–200 and 355–500 μm) was investigated to aim for the best match. Before the deposition of nanoparticles accomplished by immersion, a silanization treatment of the substrate surface was carried out. After silver nanoparticles were deposited on the porous Ti substrates, microstructural characteristics and antibacterial behavior were evaluated against the proliferation of Staphylococcus aureus on the AgNPs functionalized substrates. Finally, the preliminary qualitative analysis showed the presence of inhibitory halos, being more relevant in the substrates with larger pores. Ministry of Science and Innovation of Spain PID2019-109371GB-I00 Junta de Andalucía-Proyecto de Excelencia (Spain) P18-FR-2038 Junta de Andalucía–FEDER (Spain) US-1259771

In this work, the surface of porous titanium samples obtained by the space-holder technique was treated with a femtosecond laser to improve their osseointegration. Instrumented micro-indentation and scratch test were implemented to evaluate the tribo-mechanical behavior of the surface of the modified samples. A detailed study of micro-hardness, stiffness, scratch resistance and elastic recovery was performed. Also, in vitro analysis was carried out to evaluate the cellular behavior. Modified samples showed less ALP activity, which could indicate a greater differentiation of the cells. The cell culture was similar in all cases although more differentiated morphology, good cell adherence and biological response were observed on treated samples. Finally, the discs with a pore size between 100–200 μm present being potential candidates for the replacement of small portions of damaged cortical bone tissues. Ministry of Science and Innovation of Spain PID2019-109371GB-I00 Junta de Andalucía–FEDER (Spain) US-1259771