(PR60) Acute Hepatotoxicity of Various Bleaching Agents in ICR Mice

Objective: Several studies have shown that tooth-bleaching agents contain potentially hazardous chemicals. This study aimed to evaluate the acute hepatotoxicity of tooth-bleaching agents in ICR mice.

Methods: We randomly divided 14 female ICR mice into five groups based tooth-bleaching agent type: saline (negative control), acetaminophen (500 mg/kg, positive control), sodium perborate (50 mg/kg), 15% carbamide peroxide (50 mg/kg, Opalescence F, Ultradent), and 15% hydrogen peroxide (50 mg/kg, Trinity, SAMIL Medical, Korea). All chemicals were dissolved in a physiological saline solution and administered by intragastric gavage (periorally) daily for seven days. After seven days all animals were euthanized and blood samples collected to estimate the serum marker enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Liver sections from each group were prepared for histopathology. The specimens were evaluated microscopically (Olympus DP73, Japan) and serum biochemical levels were compared using the one-way analysis of variance test (ANOVA; p< 0.05).

Results: We did not observe significant increases in the serum levels of any biochemical. However, histopathology showed inflammatory changes, including mononuclear cellular infiltration and vascular congestion. Moderate inflammatory reaction was seen in the sodium perborate and hydrogen peroxide groups, and a mild inflammatory reaction was observed in the carbamide peroxide group.

Conclusion: Although the serum marker enzyme levels (AST, ALT) did not significantly differ from the normal levels for ICR mice in all groups, inflammatory changes were seen in all bleaching agent groups, indicating that bleaching agents may cause acute liver inflammation.