Study of DNA damage induced by dental bleaching agents in vitro

Abstract

Dental bleaching is a simple and conservative procedure for aesthetic restoration of vital and non-vital discolored teeth. Nevertheless, a number of studies have demonstrated the risk of tissue damage from the contact of these agents with the oral mucosa. In the current study, the genotoxic potential associated with exposure to dental bleaching agents was assessed by the single cell gel (comet) assay in vitro. Chinese hamster ovary (CHO) cells in vitro were exposed to six commercial dental bleaching agents (Clarigel Gold - Dentsply; Whitespeed - Discus Dental; Nite White - Discus Dental; Magic Bleaching - Vigodent; Whiteness HP - FGM and Lase Peroxide - DMC). The results pointed out that all dental bleaching agents tested contributed to DNA damage as depicted by the mean tail moment, being the strongest effect observed with the highest dose of hydrogen peroxide (Whiteness HP and Lase Peroxide, at a 35% concentration). On the other hand, Magic Bleaching (Vigodent) induced the lowest level of DNA breakage. Negative and positive controls displayed absence and presence of DNA-damaging, respectively. Taken together, these results suggest that dental bleaching agents may be a factor that increases the level of DNA damage. A higher concentration of hydrogen peroxide produced higher noxious activities in the genome as detected by single cell gel (comet) assay.

In vitro effect of low intensity laser on the cytotoxicity produced by substances released by bleaching gel

“…[7][8][9] The laser light emitting at the visible red spectrum stimulates the respiratory chain in cells under stress, leading to alterations in electron transport by mitochondria. 16,17,19,22,25 Then, besides the increase in ATP synthesis, there is signaling to the nucleus stimulating the production of antioxidant enzymes, proteins that stabilize cellular function and proliferation.…”

“…Free radicals are highly unstable and exhibit remarkable ability to react with other organic substances 7 and may even cause damage to cellular DNA. 7,8 In fact, damage to odontoblasts in vivo and fibroblasts in vitro has been reported after contact with bleaching agents. [9][10][11] Therefore, bleaching agents can release substances that lead to alteration of cellular metabolism and/or inflammation in dental pulp.…”

Genotoxic potential of 10% and 16% Carbamide Peroxide in dental bleaching

“…10,13 The mutagenicity of substances in in vitro systems should be analyzed carefully; these assays do not have the in vivo enzyme levels responsible for detoxification of the bleaching agents. 8 Animal models can also be used to characterize the toxic effects of bleaching substances.…”

“…8 However, during the bleaching process, CP breaks down into H 2 0 2 and urea, which are then dissociated into oxygen, water, ammonia, carbon dioxide, 9 and reactive oxygen species (ROS) that are considered potentially carcinogenic agents able to cause damage to proteins and changes in the cell nucleus. 10 Thus, there is a gap in the literature on the real genotoxicity of dental whitening agents in humans.…”

Genotoxicity Induced by Dental Materials: A Comprehensive Review

“…There are some studies investigating the genotoxic potential of dental bleaching agents. Our own studies have demonstrated that six commercial dental bleaching agents (Clarigel Gold -Dentsply; Whitespeed -Discus Dental; Nite White -Discus Dental; Magic Bleaching -Vigodent; Whiteness HP -FGM and Lase Peroxide -DMC) were genotoxic using mouse lymphoma cells or Chinese ovary hamster cells in vitro (6,7). Toothpastes containing whitening products were also found to be genotoxic using human gingival cells in vitro (8).…”