Remineralization of human enamel in situ after 3 months: the effect of not brushing versus the effect of an F dentifrice and an F-free dentifrice.

The in situ remineralization of 100-microns-deep enamel lesions positioned in a full prosthesis just under the first molar was determined in 13 participants after 3 months. The outer surface of the samples was always flush with the acrylic surface: there was no measurable plaque accumulation on the samples. The effect of not brushing of the samples (A) is compared with the effect of brushing with a nonfluoridated dentifrice (B) or with a fluoridated paste (C) containing 1,250 ppm F. The results show that lesion depth (and mineral loss) data increase by about 50% (case A), do not change statistically in case B and decrease by about 40% in case C. The increase of lesion depth in case A is most likely due to acidic food and/or beverage intake by the participants. With respect to nonbrushing, the remineralization effect of brushing with an F-free paste is about 50% and with the fluoridated paste about 90% in 3 months. It is suggested that the remineralization efficacy of fluoridated pastes is due to the cleaning effect of the brushing by the dentifrice (presumably on the pellicle) as well as due to the fluoride effect on mineral nucleation and growth.