Penetration of gel and solution etchants in occlusal fissures

The major clinical advantage of a phosphoric acid gel etchant is its superior control during placement. However, its viscosity can impede penetration into occlusal fissures, resulting in adequate etching and decreased pit-and-fissure sealant retention. This study examined the penetration of gel and liquid phosphoric acid etchants in occlusal fissures. The depth of fissure penetration of the acids was investigated using paired, sectioned samples and evaluated with a scanning electron microscope. The etch pattern was measured from the base of the fissure to the first demonstrable evidence of etched enamel. A variable pattern of etched enamel was present at the base of the fissure to no pattern observable at distances of 15 microns from the base. A frequent finding was that debris partially or totally blocked the fissure orifice, preventing acid penetration. Utilizing a paired t-test, no statistically significant difference (0.5 less than p less than 0.8) in the fissure penetration of gel or liquid phosphoric acid etchants could be shown.