Acid Resistance of Remineralized Enamel by a Sugar-free Chewing Gum

Objectives: This study examined the effect of a sugar free chewing gum (Tablet type) containing casein phosphopeptide- amorphous calcium phosphate (CPP-ACP; Recaldent, CASRN: 691364-49-5) on an acid resistance of remineralized enamel without fluoride conditions in a human in situ model. Methods: Twenty subjects in randomized, cross-over, double-blind studies wore removable mandibular appliances with a demineralized human enamel sample. The appliances were inserted in oral environmentimmediately before gum-chewing for 20 min and then retained for another 20 min. This was performed four times per day for 14 days. Intra-oral experiment using another gum was performed after 1 week of washout time. Half of the enamel samples were covered with nail varnish after intra-oral exposure for remineralization. The enamel samples were acid challenged for 3 days in vitro, sectioned and subjected to microradiography to determine the level of mineral vol%. Results: During the second acid challenge, the mineral loss level of CPP-ACP tablet gum group showed less mean mineral loss (-2142) than that of placebo gum (-2804). The difference between the two groups was statistically significant and the probability was 0.036. The reason why there was a less mineral loss during the second acid attack for 3 days in case of CPP-ACP gum, it seems that this gum remineralizes subsurface enamel with mineral of higher crystallinity than saliva. The formation of higher crystallinity makes the mineral less soluble in acid. Conclusion: Remineralized enamel by CPP-ACP tablet gum was much higher acid resistant than placebo gum.