29Etching is not as simple as it sounds. The contribution of good etching process is more important than the best bonding agent because without proper etching even the best bonding agent does not give optimum results. Etching is not confined to ideal enamel or dentin conditions. The substrate can be a young tooth, old tooth or otherwise. This article highlights the differences in enamel and dentin etching and the factors that affect the etching process.

Keywords: Concentration; Dentin; Depth; Enamel; Etching.