Fig. 2

SEM images of the enamel surface morphology after pH cycling. Loss of surface integrity and high surface porosities are shown in (a) demineralized enamel surface and (b) control group (deionized water). The remineralized samples reveal less microporosity and a relatively smooth surface (c), SDF (d), NaF varnish (e), NSF (f), NSF + Arg. AgNPs, silver nanoparticles; NSF, nanosilver fluoride, SEM, scanning electron microscope.