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Tooth loss is common in patients struggling with dental cavities, periodontal diseases, and tumors, as well as those who abuse tobacco or drugs. In this scenario, dental implants have become the primary treatment option for complete or partial tooth loss. Dental implant failure can be caused by stress shielding phenomenon, poor osseointegration, or to bacterial infections. In the present study, a joint solution to these limitations is proposed using a variety of porous β-titanium substrates using powder Ti35Nb7Zr5Ta alloy and employing the spacer-holder approach (ammonium bicarbonate) to obtain a variety of porosity percentage (30, 40, and 50 vol%), and pore diameters in 100–200 μm, that has been characterized in terms of its size distribution, density, morphology, chemical composition, compaction ability and Vickers micro-hardness. Furthermore, porosity, microstructure (Archimedes and image analysis) and tribomechanical behavior (P-h curves and scratch tests) experiments were performed to study and characterize the porous substrates. Polyvinyl alcohol (PVA)/poly-ε-caprolactone (PCL) containing silver nanoparticles (AgNPs), as antibacterial composite, was employed to infiltrate β-Ti disks. Scanning electron microscopy was used to determine the coating morphology, thickness, and infiltration of the porous substrates. Wettability and SBF experiments were also carried out to investigate hydrophobicity and potential biofunctionality. The results suggested how the porosity of the β-Ti alloy affects the mechanical characteristics and the wettability of the substrate that was successfully infiltrated to exert an antimicrobial behavior.

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. Ministry of Science and Innovation of Spain grant PID2019-109371GB-I00 Junta de Andalucía-FEDER (Spain) Project US-1259771 Junta de Andalucía-FEDER (Spain) Project US-1380878 Junta de Andalucía (Spain) Project PAIDI 2020 P20_00671

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.

Titanium and its alloys are well known as one of the best in-vitro and in-vivo bone replacement metallic biomaterial due to its excellent balance between biomechanical and biofunctional properties. The selective laser melting (SLM) method has a lower cost and shorter manufacturing time than the conventional routes used in the fabrication of titanium alloys. In this work, Ti6Al4V sheets were manufactured by SLM (LM samples) and subsequently annealed for stress relief at 750 oC for 10 min (LM-A samples). SEM, XRD and contact profilometry measurements were carried out to characterize the elemental composition, phases and surface morphology of different samples. A micro-tribo-mechanical evaluation was also performed by micro-indentation and scratch tests. The resulting surface was rough (Ra = 9.1 ± 0.5 μm) for all samples, showing protuberances with spherical morphology. For annealed samples, an oxide layer composed of rutile and Al2O3 was observed that increased the micro-hardness of the surface in LM-A sheets. However, after removing this oxide layer, the micro-hardness of the LM-A sheets was reduced when compared to LM samples as a result of the stress relief. A direct relationship between Vickers micro-hardness and scratch resistance was always observed. Therefore, LM-A sheets showed higher scratch resistance at low loads (oxidized surface effect) than LM samples, but lower resistance at high loads (bulk effect).