Effect of addition of citric acid and casein phosphopeptide-amorphous calcium phosphate to a sugar-free chewing gum on enamel Remineralization in situ

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) has been shown to remineralize enamel subsurface lesions in situ. The aim of this study was to investigate the effects of CPP-ACP in a fruit-flavoured sugar-free chewing gum containing citric acid on enamel remineralization, and acid resistance of the remineralized enamel, using an in situ remineralization model. The study utilized a doubleblind, randomized, crossover design with three treatments: (i) sugar-free gum ( 2 pellets) containing 20 mg citric acid and 18.8 mg CPP-ACP, (ii) sugar-free gum containing 20 mg citric acid alone, (iii) sugar-free gum not containing CPP-ACP or citric acid. Ten subjects were instructed to wear removable palatal appliances, with 4 half-slab insets of human enamel containing demineralized subsurface lesions and to chew gum ( 2 pellets) for 20 min 4 times per day for 14 days. At the completion of each treatment the enamel half-slabs were removed and half of the remineralized lesion treated with demineralization buffer for 16 h in vitro. The enamel slabs ( remineralized, acid-challenged and control) were then em- bedded, sectioned and subjected to microradiography to determine the level of remineralization. Chewing with gum containing citric acid and CPP-ACP resulted in significantly higher remineralization ( 13.0 +/- 2.2%) than chewing with either gum containing no CPP-ACP or citric acid ( 9.4 +/- 1.2%) or gum containing citric acid alone ( 2.6 +/- 1.3%). The acid challenge of the remineralized lesions showed that the level of mineral after acid challenge was significantly greater for the lesions exposed to the gum containing CPP-ACP. Copyright (c) 2007 S. Karger AG, Basel