As zinc has been included in several oral health products as an antica
lculus and antiplaque agent, the interaction of zinc with a synthetic
phosphate was investigated. The synthetic calcium phosphate used in th
is study was beta-tricalcium phosphate, or whitlockite, which is a maj
or constituent of mature calculus. The aim of this work was to study t
he mechanism of uptake of zinc to this mineral. Zinc was readily taken
up by the calcium phosphate to a maximum level of 13.9 mu mol/m(2). T
he interaction was reversible and followed a Langmuir adsorption isoth
erm. There was no concomitant release of calcium with zinc uptake. Inc
lusion of calcium in the exposure solution did however marginally depr
ess the acquisition of zinc (12% max), but fluoride had no significant
effect on uptake.