The Effect of Fluoride Varnish on Enamel Shear Bond Strength of Pit and Fissure Sealants

摘要

Purpose: The purpose of this study was to determine the effects of fluoride varnish on the enamel shear bond strength of pit and fissure sealants. Methods: Ninety-six teeth were divided into three duplicated test groups: sealant (S)/sealant thermocycle (ST) received Clinpro Sealant only; varnish sealant (VS)/varnish sealant thermocycle (VST) received five percent sodium fluoride (NaF) varnish plus sealant (VPS); and VPS/VPS thermocycle (VPST) received NaF, polish with Clinpro Prophy Paste, plus sealant. One set of each group (ST, VST, VPST) was thermocycled to represent aging, and one set (S, VS, PVS) was not. The shear bond strengths for the thermocycled groups and nonthermocycled groups were determined, and two-way analysis of variance tested the effects of thermocycling and varnish. Results: Thermocycling did not have a significant effect on the peak stresses of the groups (P=0.0552), so sets were combined. The peak stress for S/ST was significantly higher than for VS/VST (P<0.0001). The peak stress for VPS/VPST was significantly higher than for VS/VST (P<0.0001). The peak stress for S/ST was significantly higher than VPS/VPST (P=0.025). Conclusion: Fluoride varnish applied immediately before pit and fissure sealant placement negatively affected the shear bond strength of the sealant. Mechanically cleaning a fluoride varnish-coated tooth with prophy paste did not provide pit and fissure sealant enamel shear bond strengths comparable to those of untreated enamel.