Dentinal Tubule Occluding Effect of Potassium Nitrate in Varied Forms, Frequencies and Duration: An In vitro SEM Analysis.

Introduction: Dentinal hypersensitivity is an exaggerated response to non-noxious sensory stimuli (osmotic, thermal or mechanical changes). An inverse relationship between occluding open tubules and the intensity of sensitivity has been reported. Studies on the efficacy of potassium nitrate used in different forms and frequencies to occlude dentinal tubules are scarce.

Aim: To evaluate, in vitro the dentinal tubule occluding effect of potassium nitrate which differ in form, frequency and duration of application.

Materials And Methods: In an in vitro study, 45 extracted human maxillary and mandibular premolars were sectioned using diamond disc to obtain 90 samples which were treated with 6% citric acid and were randomly assigned to three groups: Group 1 was treated with potassium nitrate toothpaste (once and twice daily for two minutes); Group 2 with potassium nitrate mouthwash (once and twice daily for two minutes) and Group 3 served as control (distilled water). Post-treatment, the samples were immersed in distilled water. The samples were subjected to Scanning Electron Microscopy (SEM) at the end of 3, 7 and 14 days. SEM photographs were analysed based on extent of tubular occlusion. Chi-square test was applied to assess the significant difference between the groups.

Results: There was detectable difference in the dentinal tubule occlusion at the end of 3, 7 and 14 day between three groups. When compared to the mouthwash, toothpaste yielded better results. Twice daily application for a period of two minutes each was better when compared to once daily for two minutes.

Conclusion: Potassium nitrate is effective in occluding dentinal tubules when applied twice daily in toothpaste form than mouthwash form. However, randomised control trials are needed to confirm its efficacy in human subjects.