Effect of Different Etching Times on Pit-and-Fissure Sealant Micro-Shear Bond Strength to the Enamel of Primary Teeth

Successful clinical use of pit-and-fissure sealants relies on the sufficient etching of the enamel, field isolation and sealant retention. The etching time changes the physical and mechanical surface properties of the etched tooth tissues; therefore, it impacts both etching depth and the bond strength of sealants to the enamel. We examined if reducing the recommended 15 s etching time of primary teeth enamel affects the micro-shear bond strength (mu SBS) of pit-and-fissure sealants. The cusps of forty non-carious, extracted human primary molars were separately etched for 8, 15 or 30 s. Then, a pit-and-fissure sealant was placed and light-cured. The mu SBS values were evaluated and compared among the three groups. The mean mu SBS values +/- standard deviations were 34.68 +/- 16.93, 34.19 +/- 17.35 and 36.56 +/- 16.57 MPa in the cusps etched for 8, 15 and 30 s, respectively. No statistically significant differences in mu SBS were observed among the three test groups. In this study, we showed for the first time that the recommended etching time of primary teeth enamel may be reduced from 15 to 8 s without compromising the mu SBS of the sealant. Further evaluations in a clinical setting are warranted.