Evaluation of the efficacy of two potassium nitrate bioadhesive gels (5% and 10%) in the treatment of dentine hypersensitivity. A randomised clinical trial.

Aim: A randomised clinical trial was designed to compare the immediate efficacy (48-96 h) of two treatments with bioadhesive gels with different concentrations of potassium nitrate (NK 5% versus NK 10%) on dentine hypersensitivity (DH). We evaluated DH by means of the use of the evaporative stimulus (ES), as the main outcome, using a placebo control group as reference.
Patients and Methods: Forty-five consecutive patients who, after stimulation with a blast of air, had at least one tooth with DH > or = 2 according to the verbal ratings scale (VRS) scale were selected. They were randomly treated with a bioadhesive gel with 5% NK, 10% NK or a placebo gel without NK. The DH was evaluated at baseline, days 2, 4, 7 and 14 by an examiner blind to the procedure. The response to the ES with a blast of air, to the tactile stimulation with a probe and the subjective evaluation of the patient measured on the VRS scale were recorded. Statistical analysis was made using the Kruskal-Wallis test.
Results: A greater reduction of DH after ES was observed after 48 h of treatment in the NK10% group (35.8%) compared to the NK5% group and placebo group (11.8% and 13.4%, respectively). This difference increased significantly at 96 h (p=0.003). No significant differences were observed for the other variables. These preliminary results may support the usefulness of an NK 10% gel to reduce the DH after stimulation with a blast of air during the first 4 days of its appearance.