The effect of acid primer or conventional acid etching on microleakage in a photoactivated sealant

PURPOSE: The purpose of this study was to examine differences in microleakage in extracted human teeth when placing sealants using conventional acid etching or an acidic primer resin. METHODS: Three experimental groupings were used: group 1--conventional acid etching with placement of light-cured sealant; group 2--application of acidic primer resin (Prompt-L-Pop) and light curing, followed by sealant placement; group 3--similar to group 2, but acidic primer and sealant were photocured after placement of sealant. Teeth were thermocycled, stained, sectioned and examined for marginal microleakage. RESULTS: In group 1, 94% of the enamel-sealant interfaces were free of microleakage. For groups 2 and 3, only 28% showed no leakage, with most leakage occurring at both margin and base areas. Nonparametric data analysis indicated acid etching demonstrated significantly lower microleakage than either treatment using the acidic primer resin (P<.001) and that leakage scores in the acidic primer groups were identical (P=.4011). CONCLUSIONS: Use of this specific acidic resin primer in lieu of conventional acid etching (whether cured prior to or subsequent to sealant placement) demonstrated greater incidence of microleakage and would not be advocated over traditional etching procedures.