gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2018)

23.10. - 26.10.2018, Berlin

New generation of ceramic coatings for implants and medical instruments

Meeting Abstract

  • presenting/speaker Antonio Santana - IHI Ionbond AG, Olten, Switzerland
  • Roman Heuberger - RMS Foundation, Bettlach, Switzerland
  • Ayat Karimi - EPFL, Institute of Physics (IPHYS), Lausanne, Switzerland
  • Thomas Imwinkelried - RMS Foundation, Bettlach, Switzerland
  • Nico Goebbels - IHI Ionbond AG, Olten, Switzerland
  • Susann Schmidt - IHI Ionbond AG, Olten, Switzerland
  • Markus Tobler - IHI Ionbond AG, Dulliken, Switzerland

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2018). Berlin, 23.-26.10.2018. Düsseldorf: German Medical Science GMS Publishing House; 2018. DocPT19-910

doi: 10.3205/18dkou698, urn:nbn:de:0183-18dkou6983

Veröffentlicht: 6. November 2018

© 2018 Santana et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objectives: The requirements and spectrum for coatings on implants and surgical instruments increase steadily, calling for innovative coatings, application technologies and processes. For example, patients receive joint replacements at a younger age or live longer, active lives, which in turn requires improved implant longevity.

Ceramic coatings on joint replacements may inhibit metal ion release from the bulk material and decrease corrosion as well as wear, while the tough bulk material is preserved. This leads to less inflammation, pain and reduces the number of expensive revision surgeries. Such challenges are already tackled using older generations of bio-compatible cathodic arc coatings. However, these require extensive post-processing procedures. In contrast, the next generation of coatings using innovative processes together with novel deposition technologies render an improved performance as such coatings are dense and virtually defect free.

Here, we present results on the performance of hard ceramic or carbon based coatings deposited with new vacuum plasma technologies and benefits of such for implant bearing scenarios. New coating developments are also applied onto surgical instruments representing extensive improvements in anti-reflection properties as well as cleaning and sterilization cycles.

Methods: Ceramic coatings (SiN, TiN, TiNbN and a-C:H) were deposited to a thickness of 5 µm on different substrate materials (steel 1.2379, CoCrMo, TiAlV) as well as CoCrMo knee and hip head implants. Initially, the average roughness (Ra) of steel was < 30 nm, while CoCrMo and TiAlV were polished to Ra < 10 nm. Ceramic coatings and a-C:H were deposited in industrial units using pulsed magnetron sputtering and plasma activated chemical vapor deposition, respectively. Ceramic nitride coatings were deposited in N2/Ar gas mixtures, while a-C:H was deposited in C2H2. After deposition, the coatings were analyzed in order to investigate their composition, structure and to assess their performance.

Results and conclusion: A significant reduction of droplets and pinholes was observed for the next generation of ceramic coatings, resulting in Ra values of < 25 nm compared to earlier, corresponding coatings with Ra values above 75 nm. Hardness values of up to 30 GPa and an improved wear resistance were measured for coatings with Metal-to-Nitrogen ratios <1 and dense a-C:H coatings. First hip simulator tests (according to ISO 14242-1:2014) suggest a significant reduction of the Cr and Co ion release by at least ten times from coated joint replacements. The TiN coating was found most efficient in inhibiting the toxic ion release. Additionally, no significant impact on wear of the highly crosslinked polyethylene (HXLPE) inlays were observed for TiN coated implants.

The ceramic coatings act anti-allergic as significantly less toxic metal ions are released. Therefore, an improved implant longevity upon ceramic nitride deposition can be estimated.