In situ clinical effects of new dentifrices containing 1.5% arginine and fluoride
on enamel de- and remineralization and plaque metabolism.
Author(s): Cantore R(1), Petrou I, Lavender S, Santarpia P, Liu Z, Gittins E, Vandeven M,
Cummins D, Sullivan R, Utgikar N.
Affiliation(s): Author information:
(1)Colgate-Palmolive Technology Center, Piscataway, NJ, USA.
Publication date & source: 2013, J Clin Dent. , 24 Spec no A:A32-44
OBJECTIVE: The primary objective of the three studies reported in this paper was
to evaluate the effects of new dentifrices containing 1.5% arginine, an insoluble
calcium compound, and fluoride for their ability to promote remineralization of
demineralized enamel, and to prevent mineral loss from sound enamel specimens. A
secondary objective was to determine the effects on plaque metabolism with
respect to the conversion of arginine to ammonia and sucrose to lactic acid.
METHODS: In Study 1, an intraoral remineralization/demineralization clinical
model was used to assess the ability to promote remineralization of enamel of two
dentifrices containing 1.5% arginine and 1450 ppm fluoride, as sodium
monofluorophosphate (MFP), relative to a positive control with dicalcium
phosphate dihydrate (Dical) and 1450 ppm fluoride, and a negative control with
Dical and 250 ppm fluoride. One of the arginine-containing dentifrices contained
Dical, and the other contained calcium carbonate as the source of insoluble
calcium. Microradiography and image analysis were used to measure mineral
changes. The study used a double-blind crossover design with a two-week treatment
period. Each treatment period was preceded by a one-week washout period. Each
product was used twice a day for two weeks. In the two other studies, the ability
of dentifrices containing 1.5% arginine and fluoride to prevent demineralization
of sound enamel blocks was assessed using an intraoral
demineralization/remineralization clinical model and a double-blind crossover
design with a five-day treatment period. A one-week minimum washout period
preceded each treatment phase. Microhardness was used to assess mineral changes.
Cariogenic challenges were administered by dipping each intraoral retainer into a
10% sucrose solution four times per day. Each product was used twice per day
during the treatment period. Plaque was harvested from the specimens to measure
the ability of the plaque to convert arginine to ammonia (Studies 2 and 3) and
sucrose to lactic acid (Study 3) at the end of each treatment period. In Study 2,
a dentifrice containing 1.5% arginine, Dical, and 1450 ppm fluoride as MFP was
compared to a matched positive control containing 1450 ppm fluoride and to a
matched negative control containing 250 ppm fluoride. In Study 3, a dentifrice
containing 1.5% arginine, calcium carbonate, and 1000 ppm fluoride as MFP was
compared to a matched positive control containing 1000 ppm fluoride and to a
matched negative control containing 0 ppm fluoride.
RESULTS: In Study 1, the percent mineral changes were +18.64, +16.77, +4.08, and
-24.95 for the 1.5% arginine/Dical/1450 ppm fluoride, the 1.5% arginine/calcium
carbonate/1450 ppm fluoride, the positive control, and negative control
dentifrices, respectively. Study validation was successfully achieved by showing
that the positive control was statistically significantly better that the
negative control in promoting remineralization (p = 0.0001). The two
arginine-containing test products were statistically significantly better than
the positive control (p < 0.05). No significant difference was observed in
efficacy between the two arginine-containing products, indicating that efficacy
in promoting remineralization was independent of the choice of Dical or calcium
carbonate as the source of insoluble calcium. In Study 2, the percent
demineralization values were -8.50, +1.67, and +12.64 for the 1.5%
arginine/Dical/1450 ppm fluoride, the positive control, and negative control
dentifrices, respectively. Study validation was successfully achieved by showing
that the positive control was statistically significantly better at preventing
demineralization than the negative control (p < 0.0001). The arginine-containing
dentifrice was shown to be statistically significantly better at preventing
enamel demineralization than the positive control (p < 0.0001). Plaque metabolism
measures for plaque exposed to the three treatments gave the following values for
ammonia production after an arginine-sucrose challenge, expressed in nanomoles
per milligram plaque: 162.7; 105.4; and 115.9 for the 1.5% arginine/Dical/1450
ppm fluoride, positive control, and negative control dentifrices, respectively.
No statistically significant differences were observed between the three
treatments, but the arginine-based dentifrice showed directionally higher ammonia
production than both the positive and negative controls In Study 3, the percent
demineralization values were +1.16, +4.96, and +15.34, for the 1.5%
arginine/calcium carbonate/1 000 ppm fluoride, the positive control, and negative
control dentifrices, respectively. Study validation was successfully achieved by
showing that the positive control was statistically significantly better at
preventing demineralization than the negative control (p < 0.0001). The
arginine-containing dentifrice was shown to be statistically significantly better
at preventing enamel demineralization than the positive control (p < 0.05).
Plaque metabolism measures for plaque exposed to the three treatments gave the
following values for ammonia production after an arginine-sucrose challenge,
expressed in nanomoles per milligram plaque: 99.6; 56.2; and 42.2 for the 1.5%
arginine/calcium carbonate/1000 ppm fluoride, the positive control, and negative
control dentifrices, respectively. Plaque treated with the arginine- containing
dentifrice produced significantly more ammonia than the positive and negative
control dentifrices (p < 0.05). No significant difference in ammonia production
was observed between the two controls. Lactic acid production after a sucrose
challenge gave the following values, expressed as nanomoles per milligram plaque:
4.06; 5.12; and 4.64 for the 1.5% arginine/calcium carbonate/1000 ppm fluoride,
the positive control, and negative control dentifrices, respectively. No
significant difference was observed between the three treatments, but the
arginine-based treatment showed directionally lower lactic acid production.
RESULTS: The results of these three studies show that dentifrices containing 1.5%
arginine, an insoluble calcium compound, and fluoride have a significantly
improved ability to promote remineralization and prevent demineralization of
enamel relative to dentifrices containing the same level of fluoride alone. Two
different sources of insoluble calcium were evaluated, Dical and calcium
carbonate. Dentifrices with Dical and with calcium carbonate, each in combination
with 1.5% arginine and fluoride, provided superior efficacy as compared to
matched dentifrices with fluoride alone, and the two products demonstrated
comparable efficacy in promoting remineralization. The results of these studies
demonstrate that the addition of 1.5% arginine to Dical-and calcium
carbonate-based fluoride dentifrices provides superior efficacy in preventing
demineralization and promoting remineralization, and, further, indicate that he
arginine-containing dentifrices enhance the ability of plaque to metabolize
arginine to ammonia.
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