The effect of etch duration on the microstructure of molar enamel: an in vitro study.

This in vitro study evaluated the influence of varying etch time on the microstructure of molar buccal enamel. The buccal surfaces of four groups of extracted first molar teeth were etched for 15, 30, 45, and 60 seconds. The etch patterns obtained were photographed with a scanning electron microscope and rated with a 3-grade scale. The 15-second etch time failed to produce any optimal etch patterns. The best etch patterns were found in molars etched for 60 seconds.