The purpose of the present study was to investigate the scanning electron microscopic texture of enamel and dentin cavity surfaces in extracted human teeth following different etching modalities, specifically combinations of etchants adapted to the tissue composition of the cavity walls. It was concluded that an etching technique that combined the action of 2 different etchants - ethylenediaminetetraacetic acid (EDTA) on dentin and phosphoric acid on enamel - optimized retention structures on each tissue surface of a dental cavity better than either 1 of the 2 etchants that were applied to both types of tissue in the cavity walls.