Plasma-Sprayed Wollastonite Coatings for Biomedical Application

Abstract

A new bioceramic coating based on wollastonite was prepared by plasma spraying. The coatings exhibited good mechanical properties. The bond strength of the coating on substrate was about 40 MPa, which is higher than that of HA coatings used in orthopedics and dentistry. The bioactivity of wollastonite coatings was evaluated in vitro and in vivo. After immersed in simulated body fluid, a bone-like apatite layer was formed on the surface of wollastonite coatings. Osteoblast could survive and proliferate on the surface of coatings. After implanted in dog’s cortical bone, histological observation demonstrated that bone tissue could extend and grow along the surface of wollastonite coatings. The coating bonded directly to bone without any fibrous tissue, indicating good biocompatibility and bone conductivity. The wollastonite coatings also showed good bone inductivity property, inducing new-bone formation on their surface after implanted in marrow. The results obtained indicated that the plasma-sprayed wollastonite coatings possessed good mechanical properties and excellent bioactivity in vitro and in vivo. It appears that a wollastonite coating may be suitable for the repair and replacement of living bone, especially for load-bearing situations.