The effect of different enamel surface treatments on the microleakage of fissure sealants

The aim of this study was to evaluate the effects of different techniques of surface treatment on the microleakage of a fissure sealant in molar teeth. A total of 50 freshly extracted noncarious human third molars were randomly assigned to one of five groups. Occlusal fissures were treated with one of the following: acid etching with 35% orthophosphoric acid (group 1); fissurotomy with a Fissurotomy Micro NTF metal bur (group 2); laser etching with an Er,Cr:YSGG laser at 2 W and 20 Hz (group 3); laser etching with an Er,Cr:YSGG laser at 2 W and 40 Hz (group 4); and air abrasion for 20 s with 30-A mu m Al2O3 particles via a CoJet Prep device (group 5). After surface pretreatment, a resin-based sealant was applied to the fissures. The sample teeth were subjected to thermocycling and stored in distilled water at 37A degrees C for 1 month. Following immersion in 0.5% basic fuchsin solution for 24 h, three buccolingual slices of each sample tooth were scored under a stereomicroscope, and the morphological appearance of the area between the enamel surface and fissure sealant was examined under a scanning electron microscope. The Kruskal-Wallis test and one-way ANOVA revealed significant differences in marginal leakage, as follows: group 1 showed significantly lower scores than groups 2 and 5, the scores of groups 1, 3 and 4 were not significantly different, and group 2 showed significantly higher scores than groups 3 and 4. Laser irradiation, the metal bur, and the CoJet Prep device did not eliminate the need for acid etching of the enamel prior to placement of a fissure sealant. Laser etching at 2 W (20 Hz or 40 Hz) may be an alternative to conventional acid-etching.