RESUMEN
PURPOSE: To determine whether ingestion of a tooth whitener containing 6% hydrogen peroxide as bleaching agent affected the gastric mucosa of adult, female laboratory rats. MATERIALS AND METHODS: Thirty-six fasting rats were intubated with a single bolus (5 g/kg body weight) of the tooth whitener Natural White which contains 6% hydrogen peroxide. Thirty-two control rats received deionized water. Rats were necropsied 15 minutes, 2 hours, 1 and 2 weeks after whitener ingestion. The gastric mucosa was examined histologically and blood hematocrit, glucose, BUN, and bilirubin measured. RESULTS: Six of the 36 rats died within 2 hours of receiving whitener. Within 15 minutes of whitener ingestion, stomachs were grossly bloated with gas. Histological observation showed that gastric mucosal cells were vacuolated and gastric glands dilated. After 2 hours, gastric epithelial and glandular cells had sloughed off into the gastric lumen. Mean blood glucose and hematocrit were significantly (P < 0.05) elevated (233 +/- 41 mg/ml and 50.5 +/- 0.9%) over mean control values (129 +/- 8 mg/ml and 42.8 +/- 2.4%). Within 1 week, the stomachs of experimental rats were no longer bloated, the gastric mucosa appeared normal histologically, but mean blood hematocrit was significantly (P < 0.05) decreased (38.0 +/- 1.5%) from mean control value (43.3 +/- 0.5%). There were no significant differences in mean blood values 2 weeks after whitener ingestion.
Asunto(s)
Peróxido de Hidrógeno/toxicidad , Medicamentos sin Prescripción/toxicidad , Blanqueamiento de Dientes/efectos adversos , Enfermedad Aguda , Análisis de Varianza , Animales , Femenino , Mucosa Gástrica/efectos de los fármacos , Mucosa Gástrica/patología , Intoxicación/sangre , Intoxicación/etiología , Intoxicación/patología , Ratas , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
Tooth whiteners are considered as cosmetic agents to be used for bleaching teeth. Since tooth whitener may be swallowed during the whitening procedure, studies were conducted to determine whether ingestion of tooth whitener containing carbamide peroxide resulted in toxic effects. Adult female rats were used, and vaginal smears were examined daily to determine whether the animals were ovulating. Following an overnight fast, a single bolus of a commercial tooth whitener (5 g of tooth whitener/kg fasting body weight) was administered by gavage. Control rats received de-ionized water. After 2 h, mean respirations per min of animals receiving the tooth whitener Quik Start (contains 35% carbamide peroxide) decreased from 169 to 55, and body temperature decreased from 38.4 to 34 degrees C. Other distress signs included: labored breathing, loss of righting reflex, partial eye closure, bloody urine, and incontinence. Three of 22 animals (3/22) died within 48 h, of gastric hemorrhaging. Eight/10 rats stopped ovulating. At necropsy 2 weeks post-dosing, 10/19 animals had grossly bloated stomachs, and mucosal necrosis was observed histologically in 3. Animals receiving White & Brite or Nu-Smile (containing 10 or 15% carbamide peroxide, respectively) exhibited similar but milder symptoms. The data indicate that ingestion of large doses of commercial preparations of tooth whiteners may be acutely toxic, sometimes fatal, to female laboratory rats.