Background: the present study aims to evaluate whether fluoro calcium phospho silicate (Biomin or Elzenes) or in combination with Diode laser has better dentinal tubule occlusion and can be suggested as a effective treatment modality for patients with dentinal hypersensitivity. The objectives of the study were -to evaluate effectiveness of Fluoro calcium phospho silicate on dentinal tubules occlusion, to evaluate effectiveness of Fluoro calcium phospho silicate and laser and to compare its effect with Fluoro calcium phosphosilicate alone and laser on dentinal tubule occlusion, and to evaluate the effectiveness of laser on dentinal tubule occlusion. In study setting, SEM analysis was done at Sophisticated test and instrumentation centre, Cochin University of Science and Technology (CUSAT), Kerala. 120 Dentine specimens were obtained from sound premolars extracted for orthodontic purpose from the patients of age group 13 to 40 years. All the teeth were stored in 0. 2% thymol at room temperature. In our study, Fluoro calcium phospho silicate (Biomin) showed an average results of 70.37% completely occluded tubules and 23.48% of partially occluded tubules compared to 2.68% and 28.43% in the control group. Conclusion: In our invitro study the treated groups the specimens brushed with combination group (Biomin and Laser) showed the highest percentage of tubule occlusion followed by Biomin alone and then Laser. Hence from the results, it can be stated that combination of Biomin and laser can be considered as the best effective method in office treatment modality for dentinal hypersensitivity because of its ability to occlude more tubules.. Keywords: Diode laser, Biomin or Elzenes