Effect of Laser and Potassium Nitrate Application on the Sensitivity Control in Bleached Teeth

Effect of Low-level Light Therapy Associated With Potassium Nitrate in the Control of Post-bleaching Dental Sensitivity: a Randomized, Double-blind, Split-mouth, Controlled Trial

To investigate the effects of desensitizing agents on the dental bleaching process, testing the hypothesis that they may control dental sensitivity.

The objective of this double blind, randomized and controlled clinical study, was to evaluate the efficacy of potassium nitrate / sodium fluoride (KNO3 / KF) gel associated with LLLT (Low Level Light Therapy) on teeth that were exposed to 35% hydrogen peroxide during 3 weeks of bleaching treatment. Methods: 50 volunteers were evaluated through the split-mouth model, where the hemiarcates were randomized and later allocated in one of the experimental groups: G1 (negative control)- group with no desensitizing treatment, only bleached; G2 (positive control)- group treated with LLLT + placebo gel; G3- group treated with placebo laser application + 5% KNO3 / 2% KF gel; and G4- group treated with LLLT + 5% KNO3 / 2% KF gel.

Inclusion Criteria:

• Absence of active carious lesions;
• Never undergone bleaching therapy;
• Good oral hygiene;
• Do not present hypersensitivity;
• Do not smoke;
• Not being pregnant;
• Presence of at least 28 teeth in oral cavity.

Exclusion Criteria:

• Presence of periodontal disease;
• Presence of cracks or fractures;
• Presence of restorations and prostheses;
• Presence of gastroesophageal dysfunction;
• Patients with severe internal dental dimming;
• Presence of periodontal disease;
• Presence of dentin exposure in anterior and/or posterior teeth.