 Recent studies suggest that water fluoridation, particularly in industrialized countries, may be unnecessary because topical fluorides (such as in toothpaste) are widely used and caries rates have become low.For this reason, some scientists consider fluoridation to be unethical due to "the debilitating effects of fluoride toxicity" and the lack of informed consent.Although fluoridation can cause dental fluorosis, which can alter the appearance of developing teeth or enamel fluorosis, the differences are mild and usually not considered to be of aesthetic or public-health concern.