Bioactivity response of Ta 1-x O x coatings deposited by reactive DC magnetron sputtering

Abstract

The use of dental implants is sometimes accompanied by failure due to periimplantitis disease and subsequently poor esthetics when soft-hard tissue margin recedes. As a consequence, further research is needed for developing new bioactive surfaces able to enhance the osseous growth. Tantalum (Ta) is a promising material for dental implants since, comparing with titanium (Ti), it is bioactive and has an interesting chemistry which promotes the osseointegration. Another promising approach for implantology is the development of implants with oxidized surfaces since bone progenitor cells interact with the oxide layer forming a diffusion zone due to its ability to bind with calcium which promotes a stronger bond. In the present report Ta-based coatings were deposited by reactive DC magnetron sputtering onto Ti CP substrates in an Ar+O2 atmosphere. In order to assess the osteoconductive response of the studied materials, contact angle and in vitro tests of the samples immersed in Simulated Body Fluid (SBF) were performed. Structural results showed that oxide phases where achieved with larger amounts of oxygen (70 at.% O). More compact and smooth coatings were deposited by increasing the oxygen content. The as-deposited Ta coating presented the most hydrophobic character (100°); with increasing oxygen amount contact angles progressively diminished, down to the lowest measured value, 63°. The higher wettability is also accompanied by an increase on the surface energy. Bioactivity tests demonstrated that highest O-content coating, in good agreement with wettability and surface energy values, showed an increased affinity for apatite adhesion, with higher Ca/P ratio formation, when compared to the bare Ti substrates.

Surface Treatments and Functional Coatings for Biocompatibility Improvement and Bacterial Adhesion Reduction in Dental Implantology

“…Tantalum promotes bone ingrowth by establishing osseoincorporation that will enhance the secondary stability of implants in bone tissue and is more osteoconductive than titanium or cobalt-chromium alloys. [123] Oxidized Ta-based coatings were deposited by reactive DC magnetron sputtering onto Ti CP substrates in an Ar + O 2 atmosphere [124]. Bioactivity tests demonstrated that highest O-content coating showed an increased affinity for apatite adhesion, with higher Ca/P ratio formation, when compared to the bare Ti substrates.…”

Influence of Oxygen content on the electrochemical behavior of Ta1-xOx coatings

“…A complete structural analysis of the coatings was previously performed and can be found in previous publication [18]. Briefly, Xray diffraction analysis showed three fundamental behaviors: (i) Ta1 coating revealed a crystalline body-centered cubic phase (bcc), characteristic a-Ta phase; when the oxygen content increases to 11 at.…”

“…However, Ta presents higher prices and density comparatively with other metals [15,17]. Hence, the objective of this work is to coat stainless steel 316L (SS 316L) with Ta 1-x O x films to combine the enhanced bioactivity of Ta-based materials [18] with the low cost of SS 316L and evaluate the system corrosion resistance in artificial saliva.…”

Development of stacked porous tantalum oxide layers by anodization

“…Anodized Tantala is typically used in capacitors and as protective coating material for chemical equipment (e.g. optical devices) [19], but is also used in medical devices due to its enhanced bioactivity [20]- [23]. In addition, due to its excellent dielectric properties, it seems to be also an excellent option in electronic and sensor devices [19], [24], [25].…”