Cytotoxic Effects of Zoom® Whitening Product in Human Fibroblasts

Abstract

Tooth whitening procedures are increasing; however, side effects can occur, such as damage to pulp cells, by the whitening products. This study aims to assess the cellular effects promoted by a whitening product, namely, the oxidative stress fostered by the active agent hydrogen peroxide, with and without photoactivation. Additionally, if cellular recovery occurred, we intended to determine the time point where cells recover from the tooth whitening induced damage. Human fibroblasts were exposed to hydrogen peroxide, Zoom®, Zoom® + irradiation, and irradiation alone. The following analysis was performed: metabolic activity evaluation by the MTT assay; cell viability, mitochondrial membrane potential, peroxides production, superoxide radical production, and reduced glutathione expression by flow cytometry. We determined the IC50 value for all groups, and a dose-dependent cytotoxic effect was verified. At the times analyzed, hydrogen peroxide groups showed no metabolic activity recovery while a cell recovery was observed after 24 h (Zoom®) and 48 h (Zoom® + irradiation). Cell death was seen in hydrogen peroxide and Zoom® + irradiation groups, mainly by apoptosis, and the irradiation had a cytotoxic effect per se. This in vitro study supports that whitening products with moderate hydrogen peroxide (HP) concentration have a temporary effect on cells, allowing a cellular recovery.

Development of a hydroxyapatite nanoparticle-based gel for enamel remineralization —A physicochemical properties and cell viability assay analysis

“…The mouse fibroblast NIH/3T3 cell line is one of the widely employed cell lines most sensitive to chemicalinduced cytotoxicity in toxicity tests of dental materials 40) . Cell-based cytotoxicity tests are a widely accepted methodology for testing dental materials' cytotoxicity, with fibroblast cells being a convenient and reproducible model, as listed by ISO/EN10993-5 [41][42][43] .…”

The Effect of Selected Dental Materials Used in Conservative Dentistry, Endodontics, Surgery, and Orthodontics as Well as during the Periodontal Treatment on the Redox Balance in the Oral Cavity

“…Tooth whitening is one of the most frequently chosen procedures to restore the esthetics of discolored teeth. Whitening can be performed both in the dental clinic and at home [ 126 , 127 ]. Hydrogen peroxide (H 2 O 2) is the most commonly used substance for this purpose due to its low price and high effectiveness [ 83 ].…”

“…Interestingly, hydrogen peroxide can diffuse through the enamel to a concentration of about 0.01% in the pulp. Recent studies suggested that the higher the content of whitening agents such as hydrogen peroxide, the greater the cytotoxic effect on the pulp [ 127 ]. Cytotoxicity increases significantly after using a LED lamp with a wavelength from 400 to 505 nm.…”

“…Cytotoxicity increases significantly after using a LED lamp with a wavelength from 400 to 505 nm. In the study group using 0.01% hydrogen peroxide, a considerable increase in ROS production as well as boosted apoptosis on the mitochondrial pathway were demonstrated, which was associated with a decreased number of living cells in this group [ 127 ]. However, it was shown that the pulp after whitening undergoes regeneration within 24 to 72 h, which indicated a temporary cytotoxic effect [ 127 ].…”

“…In the study group using 0.01% hydrogen peroxide, a considerable increase in ROS production as well as boosted apoptosis on the mitochondrial pathway were demonstrated, which was associated with a decreased number of living cells in this group [ 127 ]. However, it was shown that the pulp after whitening undergoes regeneration within 24 to 72 h, which indicated a temporary cytotoxic effect [ 127 ]. Lima et al [ 130 ] also demonstrated that the use of antioxidants such as sodium ascorbate (0.25 mM/0.5 mM) reduces ROS production, thus limiting the risk of OS development (85).…”