The aim of this study was to evaluate the concentration and pH stability of four different 10% carbamide peroxide products: Opalescence PF 10% (OP), Whiteness Perfect 10% (FGM), Potenza Bianco PF 10% (PHS), and Power Bleaching 10% (BM4). The concentration of the products was obtained using the iodometry technique, and the pH was evaluated with a pH meter. The products were stored at room temperature and measurements were taken every 2 months for a period of 12 months. The data were analyzed and submitted to the Kruskal–Wallis non-parametric test complemented by Dunn (p <0.05). The results showed that all the groups presented significant variation in concentration, except group BM4. However, groups BM4 and FGM presented slightly more acid pH values throughout the study period. It was concluded that all products evaluated in this study presented acceptable stability within the international standards for bleaching agents. Vital tooth bleaching is usually performed using carbamide peroxide gel, which releases free radicals that oxidize the pigment molecule, while also generating oxidative stress in the pulp tissue. Bleaching gels that are more stable have better control of the release of these free radicals and have reduced adverse effects.
Clinical relevance: Stable bleaching gels are safer for clinical use, as they gradually release free radicals, decreasing the oxidation of pulp tissue.
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