What is the optimum fluoride concentration needed for the remineralization process?

In vitro experiments could demonstrate that only negligible amounts of fluoride are necessary to promote remineralization of incipient caries lesions. From the clinical point of view, there is evidence that only under certain circumstances is a stabilization of the surface zone of an incipient caries lesion the true mechanism of action of topically applied fluorides. However, an optimum universally valid fluoride concentration needed for this process cannot be defined. Copyright 2001 S. Karger AG, Basel.