Remineralization by Chewing Gum Containing CPP-ACP and Citric Acid

Objectives: Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) have 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 the acid resistance of the remineralized enamel, using an in situ remineralization model. Method: The study utilized a double blind, randomized, crossover design with three treatments: (i) sugar-free gum (2 pellets) containing 18.8 mg CPP-ACP and 20 mg citric acid, (ii) sugar-free gum containing 20 mg citric acid alone, and (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 (4times/d, 14d). At the completion of each treatment the enamel half-slabs were removed and half of the remineralized lesion treated with carbopol/lactic acid for 16hr. The enamel slabs (remineralized, acid challenged and control) were then embedded, sectioned and subjected to microradiography to determine the level of remineralization. Results: Chewing with the gum containing CPP-ACP and citric acid resulted in significantly higher remineralization (13.1% ± 2.2%) than chewing with either the gum containing no CPP-ACP or citric acid (9.3% ± 1.2%) or the gum containing citric acid alone (2.6% ± 1.3%) (p<0.01). The 16hr acid challenge of the remineralized lesions showed that the level of mineral after acid challenge was significantly greater for the gum containing CPP-ACP and citric acid when compared with the other two gums (p<0.01). Conclusion: Sugar-free chewing gum containing CPP-ACP and citric acid significantly promoted remineralization of enamel subsurface lesions in situ.