Etching of young permanent teeth with acid gel--a comparison between the effect of 15 seconds & 60 seconds of etching.

The purpose of present study was to compare the effect of 15 seconds & 60 seconds of etching of young permanent teeth in vitro with 50% phosphoric acid gel using scanning electron microscope. 25 pairs of enamel surfaces selected for the study were divided into 3 experimental groups. The control group consisted of unetched enamel surfaces. In Group II, the effect of 50% phosphoric acid gel was compared with 37% phosphoric acid solution for 15 seconds whereas in group III, the effect of 15 seconds & 60 seconds of etching with 50% phosphoric acid gel was compared. The degree of etching pattern was evaluated by using scoring pattern from 1-3. Results showed no significant difference between the etching pattern obtained with the use of 37% solution and 50% gel for 15 seconds. But it was observed that etching with 50% for 15 seconds resulted in equal or even an enhanced etching pattern as compared to the pattern obtained in 60 seconds with 50% phosphoric acid gel.