Tray delivery of potassium nitrate-fluoride to reduce bleaching sensitivity

Objective: Tooth sensitivity is a common side effect associated with tooth whitening. The purpose of this study was to determine if bleaching tray del ivery of potassium nitrate-fluoride reduces bleaching sensitivity enough to allow continuation of whitening treatment. Method and materials: Thirty pa tients were enrolled in a university-approved clinical study and had their teeth bleached at night with 10% carbamide peroxide in a custom-fitted tray . The bleaching tray was a rigid experimental design for which sensitivity was expected. If tooth sensitivity was experienced, the patient applied a g el containing 5% potassium nitrate and 1,000 ppm sodium fluoride in the ble aching tray for Various time periods. Log forms were collected upon complet ion of bleaching, and patient interviews were used to compare effects of th e gel before and after sensitivity treatment. Results: Sixteen out of 30 pa tients experienced tooth sensitivity. Of those 16 patients, 12 used the gel , and 11 of the 12 reported a reduction in sensitivity. Treatment times ran ged from 10 minutes before bleaching to 30 minutes before and after. The nu mber of applications ranged from one to continuous use. Some patients were able to continue bleaching after one gel application with no subsequent sen sitivity, Other patients were unable to continue bleaching unless they cont inued using the gel. The incidence of tooth sensitivity (53%) reported in t his study is consistent with sensitivity reported in studies using semi-rig id custom-fitted trays made from stone casts with a nonscalloped, nonreserv oir design. Conclusion: The use of a 5% potassium nitrate-fluoride gel appl ied in the tray as needed for tooth sensitivity associated with nightguard vital bleaching can reduce sensitivity in a majority of patients and allow most patients to continue bleaching to completion.