effect of different etching times on subsequent depths of ground primary enamel A scanning electron microscopic study

Labial surfaces of 30 caries free recently exfoliated primary teeth were used in this study. Outer, middle and inner enamel layers were ground on the same labial surface of each tooth. All teeth were etched 37% phosphoric acid gel for 20, 30, 60, 90 and 120 seconds. The results are given in details