Figs 2A to E.

After 5-day interval bleaching, antioxidant and remineralization treatment period, the specimens showed different surface morphology: (A) Unaltered enamel surface, (B) an eroded pattern was noted with narrow cracks and granular material in some areas, (C) thin fibrillar network pattern formed a covering of the entire surface hence obscuring the underlying mild surface alterations, (D) widespread erosions and a mutilayered appearance due to formation of globular structures and aggregations was seen and (E) a relatively smooth surface with tiny depressions all over