Objective: The aim of this study was to analyse the fluoride, calcium and phosphate ion release from a range of calcium-containing dental varnishes.
Method: Five varnishes were selected for analysis: 1) Enamel Pro varnish containing amorphous calcium phosphate; 2) Clinpro white varnish containing functionalised tricalcium phosphate (fTCP); 3) Bifluorid 5 containing calcium fluoride; 4) MI varnish containing casein phosphopeptide amorphous calcium phosphate (CPP-ACP); and 5) Duraphat varnish (no added calcium positive control). The varnishes were applied to a standardised surface area of polyvinyl chloride (n=7 per group) and immersed in 25g of distilled deionised water which was changed at 1, 4, 24, 72 and 168 hours. The ion release was determined by ion chromatography and expressed as cumulative ion release as mg per g of varnish.
Result: All varnishes released measurable fluoride and calcium however only MI varnish and Enamel Pro varnish released notable levels of phosphate. At 24 hours the order of cumulative fluoride release was: 4>1>3>2=5. At 72 and 168 hours the cumulative calcium release was: 4>3>1>2=5. At 24, 72 and 168 hours the cumulative phosphate release was: 1>4>2>3=5.
Conclusion: MI varnish containing CPP-ACP had the highest release of calcium and fluoride ions. All calcium-containing varnishes except for Clinpro white containing fTCP released substantially more calcium than the positive control.