Graded changes in enamel component volumes resulted from a short tooth bleaching procedure

•Proportion of the enamel layer affected by short tooth bleaching is unknown.•After a short bleaching, enamel components were analyzed from the surface inward.•At the surface, a gradient of probability of changes followed the order: mineral>organic>water>permeability.•Probability of changes decreased from the surface inward, but followed the same order seen at the surface.•Despite negligible proportion of affected enamel layer, tooth shade changed significantly.