The second alternative is the development of dentifrices
with low fluoride concentration, which are already
available in many countries. Some studies did not found
significant differences in the anticaries effectiveness
between the fluoride toothpastes with low (500-550 ppm)
and standard concentration of fluoride (1.000-1.1000
ppm) (17,18). Nevertheless, some other researches are still
controversial when considering the effectiveness of low
fluoride toothpastes (19, 20). However, several studies
assessed children older than 6 years old, which are not
in risk of dental fluorosis anymore. We cannot assume
that similar results would be seen in primary teeth as in
permanent teeth since the literature indicates that there
may be differences between primary and permanent
enamel in reactivity to cariogenic challenges (21). In
addition, the oral cavity of young children (2–6 years
old) is much smaller than that of children aged 12 or
more, so the amount of F necessary for caries preventive
effects may not be the same in these age groups. Without
the confirmation of studies that show their anticaries
effectiveness, it seems that the best balance between
the prevention of caries and dental fluorosis is obtained
with low concentrations, approximately 400-550 ppm
of fluoride, in preschool children (17, 22). The choice of