OXIDE CERAMIC COATINGS ON ORTHOPAEDIC IMPLANTS: A REVIEW OF TiO₂ AND Al₂O₃

Abstract

Ceramic coatings like TiO₂ and Al₂O₃ have shown great promise in enhancing the surface properties of metallic orthopaedic implants. This comprehensive review summarises the latest advances in deposition techniques, performance evaluations, and the clinical outcomes of TiO₂ and Al₂O₃ coated implants. Magnetron sputtering enables uniform and adherent TiO₂ and Al₂O₃ coatings, but has limitations in coating complex geometries. Micro-arc oxidation can rapidly produce thick porous oxide layers directly on the implant, but the precise control of coating properties is difficult. Numerous studies demonstrate TiO₂ coatings can significantly improve the corrosion resistance, wear resistance, and antibacterial properties of Ti, Co-Cr, and stainless steel implants. TiO₂ coatings also appear to promote osseointegration in vitro, but TiO₂ evidence is limited. Al₂O₃ coatings reduce metal ion release and polyethylene wear for alloy implants, but long-term clinical data is sparse. While both coatings have benefits, TiO₂ demonstrates better osseointegration potential while Al₂O₃ is more bioinert. Composite coatings are being explored to harness the synergistic effects. Persistent challenges include coating stresses, thickness uniformity, durability concerns, and long-term clinical evidence.

Keywords

• tio₂
• al₂o₃
• ceramic coatings
• orthopaedic implants
• osseointegration
• corrosion
• wear