Clinical Study of Bleaching Gel Storage Temperature on Tooth Color and Sensitivity

Abstract

SUMMARY Objective: The objective of this triple-blind, split-mouth, randomized clinical trial was to evaluate the bleaching efficacy and tooth sensitivity of an in-office bleaching agent submitted to different storage temperatures (room temperature at 21.04°C±3.13°C or refrigeration at 5°C). Methods and Materials: Thirty volunteers were selected who had central incisors with color A2 or higher. The volunteers' maxillary hemi-arches received either the bleaching treatment with room temperature or refrigerated storage temperatures (two sessions of 3×15 minutes, one-week interval). Color variation was evaluated by subjective (Vita Classic and Vita Bleachedguide) and objective methods (Vita Easyshade spectrophotometer). Tooth sensitivity was evaluated with the visual analog scale (0–10) and the numerical rating scale (five points). The consistency of bleaching gels was evaluated by flow test, and pH was measured, both in triplicate. Color variation (SGU) and ΔE were analyzed by paired t-test (α=0.05). The absolute risk of pain was assessed by McNemar test (α=0.05), data from the numerical rating scale by the Wilcoxon signed-rank test (α=0.05), and visual analog scale by paired t-test. Comparison between the times within each group was analyzed by Friedman test. Gel consistency and pH were analyzed by one-way analysis of variance and Tukey post-test. Results: Regarding the absolute risk of tooth sensitivity, no significant difference was observed between the groups. The relative risk for tooth sensitivity was 1.13 (95%, confidence interval 0.70–1.82). Both tooth sensitivity scales were statistically similar. The results of the subjective evaluation (Vita Classic: p=0.73, Vita Bleachedguide: p=1.00) and the objective evaluation (p=1.00) of bleaching efficacy corresponded to the hypothesis of equality between groups after bleaching. Both pH values were around 7, and for the consistency test, there were significant differences between the groups (p=0.002). Conclusions: Storage temperature of the analyzed in-office bleaching agent had no influence on tooth color effectiveness and tooth sensitivity.

Correlation between patient satisfaction and color changes after tooth bleaching

“…This sequence corroborated the patterns observed in previous studies. 42,43 Researchers had found that alteration in b* values served as the most accurate indicator of color change. 44 Conversely, another study revealed that shifts in L* values were superior indicators of tooth bleaching effectiveness.…”

“…Two researchers who were instructed in the use of the spectrophotometer were assigned to perform the color measurements. The L *, a *, and b * values of each tooth were recorded, and the average value was calculated based on three measurements per tooth 42–45 . Measurements were taken at multiple time points: baseline (T1), after the first bleaching session (T2), after the second bleaching session (T3), 1 week after the second bleaching session (T4), and 3 weeks after the second bleaching session (T5) 46 .…”

“…The L*, a*, and b* values of each tooth were recorded, and the average value was calculated based on three measurements per tooth. [42][43][44][45] Measurements were taken at multiple time points: baseline (T1), after the first bleaching session (T2), after the second bleaching session (T3), 1 week after the second bleaching session (T4), and 3 weeks after the second bleaching session (T5). 46 The assessment of tooth color change was performed using the CIEDE2000 color-difference formula (ΔE 00 ).…”

The influence of the renewal or the single application of the peroxide gel on the efficacy and tooth sensitivity outcomes of in‐office bleaching—A systematic review and meta‐analysis

“…As a result, 14 studies were considered for eligibility. After careful examination, 10 studies were excluded because two of them did not present outcomes of interest for this systematic review, 30,31 four studies compared different commercial products, [32][33][34][35] two studies performed bleaching protocol with different full-length times, 10,36 and two studies performed the renewal of the gel in both groups 37,38 (Figure 1). Seventeen records were retrieved from other methods, but only one of them was of interest.…”

Efficacy of natural, peroxide‐free tooth‐bleaching agents: A systematic review, meta‐analysis, and technological prospecting

“…One hypothesis is that the sensitivity is caused by hydrogen peroxide molecules. These molecules diffuse through enamel and dentin, producing oxidation of tooth pigments; this chemical reaction is what provides the bleaching effect (Hortkoff, Bittencourt, Nadal, & Rezende, ). The by‐products of this reaction can reach the pulp chamber (Shackelford, Kaufmann, & Paules, ; Young, Fairley, Mohan, & Jumeaux, ) and cause serious damage to pulp tissue, especially to odontoblasts underlying dentin (Li & Greenwall, ; Moghadam et al, ; Tredwin, Naik, Lewis, & Scully, ); this may affect the regenerative potential of pulp cells, once it induces pro‐inflammatory cytokine release (Attin, Vollmer, Wiegand, Attin, & Betke, ; Soares et al, ).…”