Note: The Warren study (2009) ends with this observation: “Despite the limitations, the study provides the only recent, outcome-based assessment of the ‘optimal’ ﬂuoride intake, and as such, it appears that while the generally accepted range of 0.05 to 0.07 mg F/kg bw may still be associated with caries prevention, it may not be optimal in preventing ﬂuorosis. Of course, given that most caries prevention is believed to be as a result of topical exposures, it may be of little lesser consequence as to what the ‘optimal’ ﬂuoride intake level is for caries prevention. By the same token, while limiting ﬂuoride intake to less than 0.05 mg F/kg bw may be appropriate to prevent ﬂuorosis, given that most ﬂuorosis were mild even at higher intake levels, recommendations to limit ﬂuoride intake to less than 0.05 mg F/kg bw may not be justiﬁed. Thus, given that the present study found considerable overlap among caries/ﬂuorosis groups in terms of mean ﬂuoride intake and extreme variability in individual ﬂuoride intakes for those with no ﬂuorosis or caries history (Figure 2), ﬁrmly recommending an “optimal” ﬂuoride intake is problematic, and as stated by Burt and Eklund, perhaps it is time that ‘the term optimal ﬂuoride intake be dropped from common usage.’” Source: Ibid. Warren, et al. (2009) pp. 114-115.