Low‐fluoride toothpaste and deciduous enamel demineralization under biofilm accumulation and sucrose exposure

Cury JA, do Amaral RC, Tenuta LMA, Del Bel Cury AA, Tabchoury CPM. Low‐fluoride toothpaste and deciduous enamel demineralization under biofilm accumulation and sucrose exposure. Eur J Oral Sci 2010; 118: 370–375. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci Because low‐fluoride toothpaste (500 p.p.m. F) has not clearly been shown to be effective for controlling caries in caries‐active children, this experimental in situ study was conducted to evaluate whether its effect, when compared with a conventional toothpaste (1,000–1,500 p.p.m. F), would depend on the cariogenic challenge. During four phases of 14 d each, 14 volunteers used 500 or 1,100 p.p.m. F toothpaste and wore palatal appliances containing deciduous enamel slabs, on which biofilm was accumulated and exposed to 20% sucrose solution at frequencies increasing from two to eight times per day. The F concentration was determined in the biofilm formed, and enamel demineralization was assessed by surface hardness loss (%SHL) and integrated area of hardness × lesion depth (ΔS). The F uptake by enamel was also determined. Fluoride in biofilm fluid and solids was statistically higher when conventional F toothpaste was used. The toothpastes did not differ statistically in terms of %SHL, ΔS, and F in enamel, but only the conventional F toothpaste significantly reduced caries‐lesion progression according to the frequency of sucrose exposure. The findings suggest that the high‐F availability in biofilm, resulting from the use of conventional toothpaste compared with low‐F toothpaste, may be important for reducing caries‐lesion progression in conjunction with a high frequency of sucrose exposure.