1 Restorative
Department, Indiana University School of Dentistry, 1121 West Michigan Street,
Indianapolis, IN 46202, USA. wbrownin@iupui.edu
Abstract
Statement of the problem: Bleaching-related tooth sensitivity
has been shown to be facilitated by the presence of enamel defects. A
nano-hydroxyapatite (n-HAP) paste has been shown to repair these defects.
Purpose of the study: Using a randomized clinical trial,
an n-HAP paste was investigated to determine its efficacy in reducing
bleaching-related tooth sensitivity.
Methods and materials: An n-HAP paste (Renamel AfterBleach,
Sangi Co., Ltd., Tokyo, Japan) and a placebo (zero-HAP) were randomly assigned
for use in 42 participants. A 7% hydrogen peroxide gel was used twice daily for
14 days, with use of assigned desensitizer for 5 minutes immediately following.
A diary was completed daily for 4 weeks to note: use of the agents and
sensitivity on a visual analog scale (VAS). Three aspects of tooth sensitivity
were investigated: percentage of participants; number of days; and intensity
level. Color change was assessed.
Results: For Groups zero-HAP and n-HAP, respectively, 51 and 29% of participants
reported tooth sensitivity (p = 0.06). Days of sensitivity were 76 and 36,
respectively (p = 0.001). Change in VAS score from baseline trended higher for
group zero-HAP (p = 0.16). Color change was equivalent.
Discussion: The data trend indicated group n-HAP experienced less
sensitivity over all three measures. Only the number of days of sensitivity was
statistically significant.
Conclusion: Within the limits of the study it can be concluded
that the use of the n-HAP paste was associated with a statistically significant
reduction in the number of days of tooth sensitivity experienced during active
bleaching.
Clinical relevance: For those using a tooth whitener
without a desensitizing agent, this study indicates that a paste containing
nano-hydroxyapatite crystal can effectively reduce the duration of tooth
sensitivity.
