Work

Over-the-counter whitening strips: Evaluation of color change and hydrogen peroxide penetration into a pulp chamber

Year: 2026

Type: article

Abstract: ABSTRACT Objectives To evaluate the color change (CC) and hydrogen peroxide (HP) penetration into the pulp chamber of extracted teeth subjected to different commercial whitening strips, as well as the pH stability and surface morphology induced by these products. Materials and Methods Ninety-six premolars were randomly allocated into six groups: (1) NC, negative control (no bleaching); (2) UP, Up&Up™ Timeless White Whitening Strips; (3) LX, Lumineux® Whitening Strips; (4) CT, Crest® 3DWhitestrips™; (5) WG, Walgreens® Ultra Whitening Strips; and (6) PC, positive control (6% HP, FGM WhiteClass). CC was measured using digital spectrophotometry before treatment and 14 days post-bleaching (ΔL*, Δa*, Δb*, ΔE ab , ΔE 00, and ΔWI D ). HP penetration into the pulp chamber was analyzed using UV-Vis spectrophotometry, pH stability was measured with a pH meter, and surface morphology by scanning electron microscopy. Statistical analysis was performed using one-way ANOVA, followed by Tukey’s post hoc test (α = 0.05). Results PC, CT, and UP showed higher ΔE ab , ΔE 00 , and ΔWI D values than LX and NC. Color change was mainly driven by reductions in Δb*. HP was detected in the pulp chamber of PC, CT, and UP, with the highest levels in PC; no HP was detected in LX and NC. Only LX maintained stable pH. SEM analysis showed preserved enamel surface morphology in all groups. Conclusion HP–containing whitening strips promoted clinically relevant color changes with lower pulp chamber penetration than the at-home bleaching gel, despite a pH decrease. Peroxide-free strips were ineffective and showed no HP penetration. Clinical relevance Over-the-counter whitening strips vary in effectiveness and biological behavior according to their composition. HP-containing strips may offer effective whitening with a more conservative diffusion profile, while peroxide-free products may not achieve clinically meaningful results.

Source: Journal of Dentistry

DOI: 10.1016/j.jdent.2026.106544