Purpose:The aim of this study was to assess the effect of mouthwash, diode laser and their combination on dentin hypersensitivity(DH). Methods:Forty dentin specimens were enabled and exposed dentinal tubules were created in vitro. They are assigned into four groups; control group, mouthwash with 1.4% dipotassium oxalate, combination of the same mouthwash and 810 nm diode laser, only diode laser. The occlusion of dentinal tubules were then observed with SEM. Results:The analysis resulted with the occlusion of dentinal tubules in all treatment groups but the results were more prominent in the combined treatment group. The number of open dentinal tubules in 100µm 2 was significantly more in control group(p<0.05). Conclusion:Dentinal tubule occlusion was achieved both by mouthwash with 1.4% dipotassium oxalate and 810 nm diode laser. However, the combination of both treatments resulted with the best outcome and can be used in patients with dentin hypersensitivity.