Acid Resistance of Remineralized Enamel by a Sugar-free Chewing Gum (Recaldent^® Gum)

Y. IIJIMA1, M. NISHIMURA2, and S. IIJIMA1, 1Nagasaki University Graduate School of Biomedical
Sciences, Japan, 2Cadbury Japan, Tokyo, Japan

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 environment immediately 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.

Seq #17 - Demineralization/Remineralization

1:00 PM-2:00 PM,
Wednesday, 28 June 2006
Brisbane Convention & Exhibition Centre
Exhibit Hall 1