To evaluate the effect of a vibrating probe on sealant penetration into pits and fissures.Thirty-six extracted human third molars were used. The occlusal surface of each molar was cleaned with a rubber cup and pumice slurry. Scotchbond Etchant (35% phosphoric acid gel) was applied to the occlusal fissures of each molar for 20 seconds. Fissures were then sealed as follows: Group 1: Concise Light Cured White Sealant was applied without vibration; Group 2: same as in Group 1 but with vibration; Group 3: Single Bond Adhesive was applied, then Concise Light Cured White Sealant was applied without vibration; Group 4: same as in Group 3, but sealant was applied with vibration; Group 5: Concise Light Cured White Sealant was applied without vibration, then Z-100 composite was burnished over the sealant and light-cured; Group 6: same as in Group 5, but sealant was applied with vibration. Microvibe vibrating probe was used for sealant vibration. After 24-hour immersion in 2% basic fuchsin dye solution, specimens were sectioned, and dye and sealant penetration were scored using a stereomicroscope and color slides. Selected sectioned samples were observed under the SEM.No statistically significant differences between the groups were observed for either dye or sealant penetration scores. In all groups, sealant penetration was more influenced by the shape, depth and residual debris of fissures than by the use of a vibrating probe.