Comparative evaluation of the effectiveness of three commercially available desensitizing mouthwash on dentinal tubule occlusion: An in vitro scanning electron microscopic study

Aim: To compare and evaluate the effectiveness of three commercially available desensitizing mouthwashes on dentinal tubule occlusion in vitro using a scanning electron microscope (SEM). Materials and Methods: Twenty-seven premolar maxillary teeth were collected and cleaned to remove debris and tissue using an ultrasonic scaler. Enamel was removed with the help of a high-speed plain cut tungsten carbide fissure bur under continuous water spray. Dentinal discs measuring 5 mm x 5 mm x 3 mm were prepared from the coronal region of the extracted teeth using a double-sided carborundum disc and straight micromotor handpiece. Using carborundum paper, the discs were polished and washed with distilled water. The discs were etched using 37% phosphoric acid to remove any smear layer that was caused by the grinding process and to simulate dentinal hypersensitivity by opening the dentinal tubules. The specimens were again washed and stored in distilled water until use. Samples were then randomly allocated into Group A: calcium sodium phosphosilicate mouthwash, Group B: potassium nitrate mouthwash, and Group C: dipotassium oxalate monohydrate mouthwash. The specimens were immersed in a test tube filled with the respective mouthwash and vigorously shaken for 60 s for simulating the natural mouth rinsing action. This procedure was repeated for 7 days, twice daily. To compare and assess the proportion of dentinal tubule occlusion, all the samples were processed and examined under an SEM. Results: The efficacy of the mouthwash on the obliteration of dentinal tubules was compared using the Kruskal-Walis analysis of variance test followed by the post hoc Mann-Whitney U test for pairwise comparison. Group A showed completely occluded tubules in 5 (55.6) and mostly occluded tubules in 4 (44.4). Group B showed mostly occluded in 4 samples (44.4) and partially occluded in 5 samples (55.6) and Group C showed completely occluded tubules in 3 samples (33.3) and mostly occluded tubules in 6 samples (66.7). A P value of 0.05 or less is regarded as statistically significant. *P <= 0.05 is statistically significant. Between Group A and Group B as well as between Group B and Group C, there was a statistically significant difference. However, a statistically significant difference between Group A and Group C does not exist. Conclusion: The calcium sodium phosphosilicate group was shown to have the most occlusion of the dentinal tubule, followed by dipotassium oxalate monohydrate and potassium nitrate group.