effect of a desensitizing varnish on microleakage of two self-etch adhesives

objectives : the aim of this in-vitro experimental study was to assess the effect of application of a desensitizing varnish on the enamel and dentin marginal seal. materials and methods: seventy-two freshly extracted, intact human premolar teeth were divided into four groups (n=18). class v cavities (3mm in length, 2mm in width and 2mm in depth) were prepared on the buccal surface of each tooth. the following sealing materials were applied in the four groups: one-step clearfil s3 bond (s3) self-etch adhesive, two-step clearfil se bond (se) self-etch adhesive, s3 bond+ vivasens desensitizing varnish (vs+s3) and clearfil se bond + vivasens (vs+se). the cavities on the teeth were then incrementally filled with z350 light-cure composite. the teeth were stored in distilled water for 24 hours at 37°c, and were then thermocycled for 1000 cycles. then, all the specimens were prepared for dye penetration test and were immersed in 2% basic fuchsin dye and incubated at 37°c for 24 hours. the teeth were then sectioned buccolingually along the center of restorations with a diamond disk.   microleakage at the tooth-restoration interface was assessed in the enamel and dentin margins blindly using dye penetration under a stereomicroscope at ×20 magnification. results: there was significantly greater leakage at the enamel and dentin margins in group vs+se than in group se; also, these values were higher in group vs+s3 than in s3. conclusion: combined application of desensitizing varnish and self-etch adhesives seems to increase microleakage in composite restorations. thus, its application is not suggested.