Effect of pyrophosphate on protein adsorption to hydroxyapatite in vitro and on pellicle formation in vivo.

This study showed that pyrophosphate (PP) desorbed an acidic protein (albumin) from hydroxyapatite (HA) more effectively than phosphate and that HA pretreated with PP took up markedly less protein than untreated HA. The protein which adsorbed to PP-treated HA was more loosely bound than that adsorbed to untreated HA. In vivo experiments showed that pellicle formed more slowly on PP-treated etched enamel than on untreated controls. The possible clinical implications of these findings are discussed.