Calcium phosphate plasma-sprayed coatings and their stability: an in vivo study.

Several factors playing a possible role in determining coating stability and bone tissue response were studied in in vivo experiments. These factors involving the plasmaspray coating procedure were as follows: 1) plasmaspray powder port 2 or 6; 2) particle size distribution; 3) hydroxylapatite versus fluorapatite coatings; and 4) the effect of post-heat treatment. Coating stability and bone tissue response were examined by measuring coating thickness, coating length, and bone apposition against the coatings. The result was that heat treatment influenced coating stability significantly. Also, bone formation was more intense. Fluorapatite proved to be more stable than hydroxylapatite, which was in agreement with our previous reports.