Effectiveness of new gel with nano-hydroxyapatite in reducing dentin hypersensitivity: a double-blind randomized controlled trial.

Objectives: The present randomized double blind clinical trial aimed to compare the efficacy in reducing dentin hypersensitivity of a dentifrice gel formulation containing hydroxyapatite with a fluoride dentifrice gel and a placebo. In addition, an in vitro scanning electron microscopic (SEM) analysis was performed.
Methods: 60 subjects were recruited to participate in the study. The inclusion criteria were: hypersensitive areas on facial surfaces of the teeth with at least two teeth scoring “pain” during application of stimulus, good periodontal health with no other conditions that might explain their dentin hypersensitivity. A computer-generated random table with blocking to one of the three study treatments was used in order to have 20 subjects per group: 1) hydroxyapatite dentifrice gel; 2) fluoride dentifrice gel; 3) placebo. Groups 1, 2 and 3 were instructed to apply the gel on the teeth for 10 minutes once a day for ten days consecutively. The participant’s dentin hypersensitivity was evaluated at baseline, after 2 and 4 weeks using airblast and tactile tests. In addition a subjective evaluation using a visual analogue scale was used. Three teeth extracted for orthodontic purposes and treated according to each treatment group were examined by SEM .
Results: Significant lower values of cold air sensitivity and tactile sensitivity (p< 0.05) were found for group 1 at 2 weeks and 4 weeks compared to baseline. In addition statistically significant (p< 0.05) lower values of sensitivity were reported for group 1 compared to group 2 and 3 at 2 and 4 weeks respectively. The VAS scores were significantly lower (p< 0.05) in group 1 at 2 and 4 weeks compared to baseline.
Conclusions: The findings of the present study encourage the application of hydroxyapatite in tooth gel as an effective desensitizing agent providing quick relief from symptoms after 2 and 4 weeks.