Reactivity of a wollastonite-tricalcium phosphate Bioeutectic ceramic in human parotid saliva.

In a previous study, a new ceramic material (Bioeutectic), prepared by slow solidification through the eutectic temperature region of the wollastonite-tricalcium phosphate system, was found to be reactive in a simulated body fluid. In the present study, the reactivity of the Bioeutectic was assessed in human parotid saliva. Samples of the material were soaked for one month in human parotid saliva at 37 degrees C. The experiments showed the formation of two separate zones of carbonate-hydroxyapatite-like phase on the periphery of the samples. The first zone was formed by reaction of the bioeutectic with the saliva and progressed inside the material. The other zone developed on the surface of the bioeutectic by precipitation from the media. The mechanism of carbonate-hydroxyapatite-like phase formation in human parotid saliva appeared to be similar to that of apatite-like phase found in a simulated body fluid.