ENHANCING REMINERALIZATION OF PRIMARY ENAMEL LESIONS WITH FLUORIDE DENTIFRICE CONTAINING TRICALCIUM PHOSPHATE.
Praphasri RirattanapongKadkao VongsavanChavengkiat SaengsirinavinSumana WaideePublished in: The Southeast Asian journal of tropical medicine and public health (2018)
Fluoride dentifrice is effective in preventive dental caries but may cause
fluorosis, especially in young children. Reducing the concentration of fluoride from
the regular concentration of 1,000 parts per million (ppm) to 500 ppm can reduce
the risk for fluorosis but increases the risk of caries. Adding tricalcium phosphate
(TCP) to the dentifrices may improve the efficacy of remineralization possibly
allowing for a lower concentration of fluoride to reduce the risk of fluorosis. We
studied this to inform future caries prevention efforts in children. We immersed
40 sound primary incisors into demineralizing solution (pH=4.4) for 96 hours at
37°C to create demineralized lesions. The 40 teeth were then divided into 4 groups
of 10 teeth each. Group A: control (treated with deionized water only); Group B:
treated with fluoride dentifrice at a concentration of 1,000 ppm; Group C: treated
with fluoride dentifrice at a concentration of 500 ppm and 500 ppm TCP, and
Group D: treated with fluoride dentifrice at a concentration of 1,000 ppm and 500
ppm TCP. The teeth were each subjected to 7 days of pH-cycling and the studied
dentifrice was applied for one minute, 3 times daily during the 7 day period. After
the 7 day period the teeth were each sectioned and examined with polarized light
microscopy. The depths of demineralized areas were measured using Image-Pro
plus software. A pair t-test was used to compare lesion depths before and after
dentifrice treatment. Differences in mean lesion depths within each group were
analyzed using the One-way ANOVA and LSD tests; a 95% confidence intervals
were calculated. The mean lesion depths in all the groups before dentifrice treatment
were not significantly different (p=0.143). The mean demineralized lesion
depths after dentifrice treatment were significantly different by group (p=0.00).
The mean demineralized lesion depth in Group A significantly deeper than the
other groups (p=0.00). Group D had the shallowest depth, significantly shallower
than the other groups (p=0.006). There was no significant difference in the
mean demineralized lesion depth between Groups B and C (p=0.478). The mean
demineralized lesion depth changed significantly after dentifrice treatment in all
the groups (p=0.00). Group A was significantly deeper (p=0.00) and groups B, C
and D were all significantly shallow. Group D had the greatest reduction in mean
demineralized lesion depth (p<0.05). The 1,000 ppm fluoride plus TCP dentifrice
gave superior remineralization than the 500 ppm fluoride plus TCP and the 1,000
ppm fluoride dentifrice. The 500 ppm fluoride plus TCP gave the same remineralizing
effect as the 1,000 ppm fluoride dentifrice. TCP enhances remineralization
on primary enamel when added to fluoride dentifrice. Our results show if TCP is
added to fluoride dentifrice a lower concentration of fluoride is needed to provide
the same benefit as fluoride dentifrice with a higher concentration of fluoride,
reducing the risk of fluorosis in children.