Effects of a 10% carbamide peroxide bleaching agent on rat oral epithelium proliferation

Abstract

The purpose of the present study was to evaluate the influence of short course topical application of carbamide peroxide on proliferating cell nuclear antigen (PCNA) immunohistochemical expression in the oral tongue mucosa of rats. Twelve male Wistar rats were submitted to topical application of 10% carbamide peroxide on one side of the dorsal tongue once a week for three consecutive weeks. Only distilled water was applied on the control side. The animals were killed on days 0, 10, and 20 after the last application. The tongue was fixed in buffered formalin for 24 h and embedded in paraffin. Tissue blocks (3 µm) were subjected to the biotin-streptavidin amplified system for identification of PCNA. The percentage of epithelial-positive basal cells in each side of the tongue mucosa was calculated. The results demonstrated that topical application of 10% carbamide peroxide increases PCNA immunohistochemical expression on the basal layer of the oral mucosa epithelium of rats on day 0 after treatment. In conclusion, short-course use of carbamide peroxide induces transient epithelial cell proliferation of the oral mucosa of rats.

Influence of smoking on oral cells genotoxicity after at-home bleaching using 22% carbamide peroxide: a cohort study

“…The genotoxic potential of bleaching agents was mostly investigated by in vitro studies (cell cultures) [ 8 ] or animal models [ 29 ]. These studies use controlled peroxide concentrations (ranging from 0.03 to 30 mM) [ 30 ] resulting on a dose-dependent DNA damage increase [ 29 , 30 ].…”

“…The genotoxic potential of bleaching agents was mostly investigated by in vitro studies (cell cultures) [ 8 ] or animal models [ 29 ]. These studies use controlled peroxide concentrations (ranging from 0.03 to 30 mM) [ 30 ] resulting on a dose-dependent DNA damage increase [ 29 , 30 ]. Due to the possibility of strict control of the concentration of bleaching agent in in vitro studies, most of the time, bleaching agents can be considered genotoxic in vitro but not in vivo [ 8 ].…”

“…Distinct results obtained by the studies could be attributed to variations in the daily amount of cigarettes consumed, which is associated to MN increase in exfoliated mucosa oral cells comparing smokers to nonsmokers [ 37 ]. The volunteers of the present study used to smoke approximately a half of the cigarettes (7.6) of the previous study volunteers (13.2) [ 12 ], which could have reduced the genotoxic effect of tobacco and other substances since this is a dose-dependent response [ 29 , 30 ].…”

Carcinogenic effect of potassium bromate on tongue of adult male albino rats

“…Then, the slides were counterstained with Mayer's hematoxylin and washed in PBS and then in distilled water. The coverslips were then mounted using Canada balsam (Albuquerque et al, 2002).…”

Clinical evaluation of a new bleaching product “Polanight” in a Japanese population

“…In the past, there were many investigations of biological factors, such as the effects of the whitening agents on filling materials, [3][4][5][6] hard tooth tissues, 7,8 and oral soft tissues. 9,10 Recently, investigations of environmental factors, such as treatment time, 11,12 comparisons of effects of bleaching gels on oral bacteria, 13 and the effects of tobacco smoking, 14 have also increased. Data on long-term observations have also been accumulated.…”