←back to Blog

Tooth sensitivity and whitening effect of an in-office bleaching gel containing 2% sodium fluoride: a randomized triple-blind clinical trial

Clin Oral Investig. 2025 Apr 10;29(5):238. doi: 10.1007/s00784-025-06318-0.

ABSTRACT

OBJECTIVES: The aim of this study was to evaluate effect of adding sodium fluoride (NaF) to the in-office bleaching gel on bleaching sensitivity (BS) and tooth whitening.

MATERIALS AND METHODS: Two maxillary quadrants from 32 patients were randomly allocated to intervention and control groups in a split-mouth design. In control group, bleaching gel containing 40% hydrogen peroxide and in intervention group, the same gel with 2% NaF were applied for 45 min. Before treatment, immediately, 24 h, 7d, 30d and 90d after treatment, sensitivity to cold, touch and spontaneous stimuli was measured through Visual Analogue Scale (VAS). Color changes were evaluated by a spectrophotometer and reported through ΔE and ΔSGU values. Data were analyzed by Shapiro-Wilk, 2Q AZMann-Whiteny U, Friedman and Wilcoxon tests (α = 0.05).

RESULTS: A total of 29 patients completed the study. The cold and spontaneous sensitivity significantly decreased from baseline until 90d post-bleaching in both groups (P < 0.001), while a significant decline in tactile sensitivity demonstrated only in NaF group (p = 0.01). In the comparison between two groups, only the cold sensitivity was significantly lower in NaF group at 90d after bleaching (p = 0.040). There was no significant difference between two groups in ΔE/ΔSGU values at any of evaluation intervals.

CONCLUSIONS: The incorporation of 2% NaF into the bleaching gel significantly reduced cold sensitivity after 90d, with no detrimental effects on whitening effectiveness. (IRCT20200906048639N1) CLINICAL RELEVANCE: The in-office bleaching gel containing 2% NaF did not demonstrate a beneficial impact on BS. Nonetheless, it did not negatively affect the results of tooth whitening.

PMID:40208369 | DOI:10.1007/s00784-025-06318-0