Towards Clinical Translation: Optimized Fabrication of Controlled Nanostructures on Implant-Relevant Curved Zirconium Surfaces

Abstract

Anodization enables fabrication of controlled nanotopographies on Ti implants to offer tailorable bioactivity and local therapy. However, anodization of Zr implants to fabricate ZrO2 nanostructures remains underexplored and are limited to the modification of easy-to-manage flat Zr foils, which do not represent the shape of clinically used implants. In this pioneering study, we report extensive optimization of various nanostructures on implant-relevant micro-rough Zr curved surfaces, bringing this technology closer to clinical translation. Further, we explore the use of sonication to remove the top nanoporous layer to reveal the underlying nanotubes. Nano-engineered Zr surfaces can be applied towards enhancing the bioactivity and therapeutic potential of conventional Zr-based implants.

Dental Implant Nano-Engineering: Advances, Limitations and Future Directions

“…Recent attempts to optimize EA to enable clinical translation include fabrication of controlled nanostructures on clinical dental implants [36], superior mechanical stability (nanopores > nanotubes) [37], and fabrication of dual micro-nano structures [38] by preserving the underlying 'gold standard' micro-roughness of dental implants [39]. It is worth noting that EA is a versatile technique that can be used to nano-engineer controlled topographies on various biomedical implants, spanning various metals and alloys, including Ti [40], Ti alloys [41], Zr [42] and Al [43]. A schematic representation of TNTs and their various characteristics and research challenges is shown in Figure 1.…”

“…Zirconium (Zr) and zirconia (ZrO 2 ) are rising as dental implant material choices due to their biocompatibility, corrosion resistance and superior mechanical properties [42]. It is established that Zr 4+ ions can interact with negatively charged bacterial membranes and cause cell damage and death [148].…”

“…It is established that Zr 4+ ions can interact with negatively charged bacterial membranes and cause cell damage and death [148]. Furthermore, Zr-based implants have been electrochemically anodized in order to fabricate controlled ZrO 2 nanostructures, including nanotubes and nanopores, which can augment implant bioactivity due to their nanoscale roughness [42,149,150]. For instance, anodized Zr cylinders were placed in rat femur osteotomy models in vivo, and accelerated bone formation was obtained, in comparison with the controls of unmodified Zr [151].…”

Strategy facilitating the transfer of zirconium-oxide nanotubes onto zirconia-based ceramic implants

“…[7] In order to develop nanotubes on such surfaces, multi-step procedures start with metal deposition on the parent materials via vacuum assisted treatments such as ALD, e-beam sputtering, FDM, etc. [8][9][10][11] This technique poses numerous challenges such as adhesion of metal to substrate, stability at the interface in addition to the cost-factor to name few. The latest growing trend in biomedicine has put zirconia under the spotlight, it is a bio-inert, refractory grade metal-oxide that shares many of the characteristic properties that make up valvemetal/metal-oxide based implants favorable.…”

Nano-Engineering Solutions for Dental Implant Applications

“…Besides Ti, Zirconium (Zr) or Zirconia (ZrO 2 ) is emerging as a popular dental implant material choice attributed to its reduced affinity to bacterial plaque, appropriate mechanical properties, white colour and non-magnetic nature [14]. In a pioneering study, Chopra et al reported nano-engineering of curved and micro-rough Zr surfaces via electrochemical anodization to fabricate various nanotopographies [15]. Briefly, by optimizing anodization conditions, dental implant/abutment relevant surfaces were modified with ZrO 2 nanotubes, nanocrystals or nanopores, bringing anodization of dental implants closer to clinical translation.…”