Effect of Conditioning with Fluoride and Phosphoric Acid on Enamel Surfaces as Evaluated by Scanning Electron Microscopy and Fluoride Incorporation

Abstract
The etching effect of 50% H3PO4 applied together with 2% NaF or SnF2 was compared with the effect of H3PO4 on pre- and postfluoridated enamel by scanning electron microscopy. Substantial etching of enamel resulted with use of 50% H3PO4 with 2% NaF. High fluoride incorporation in the surface provided additional protection of the conditioned enamel.