Peroxide-release from bleaching systems in vivo - smokers versus non-smokers

Objectives: to determine peroxide release into oral cavity during use of home bleaching products by smokers and non-smokers. Peroxide release from trayless bleaching products and a conventional tray based system was evaluated with respect to safe level reported in literature. Methods: Determination of peroxide in saliva was performed with peroxidase and 4-aminoantipyrin in a photometric method. Four different bleaching regimens were used by 10 smokers (S) and 10 non smokers (NS) for 60 min each: Upper jaw teeth were bleached with individual trays charged with 500 mg Vivastyle (V). Whitestrips (WS) designed for upper jaw were used. Crest Night Effects (CN) and Colgate Simply White (SW) were painted on upper and lower incisors (160 mg). Results: Total amount of peroxide [mg] released into saliva during bleaching period was recorded (mean ± SD): Colgate Simply White: 2.67 ± 0.88 (NS); 2.66 ± 1.17 (S); Crest Night Effects: 0.23 ± 0.13 (NS); 0.25 ± 0.16 (S); Vivastyle: 2.47 ± 0.82 (NS), 2.44 ± 1.31 (S); Whitestrips: 1.39 ± 0.62 (NS), 2.02 ± 1.86 (S). Significantly lowest peroxide release was observed using CN. 3% of the charged peroxide were released into saliva from CN (SW: 30 %, WS and V: 14 – 20 %). In terms of amount/kg body weight the bleaching systems led to a single exposure of 0.004-0.046 mg/kg which is distinctly less than the safe daily dose of 0.26 mg/kg/day if calculated for a small person (58 kg). The criterion smoker vs. non smoker had no influence on peroxide levels. Conclusion: All applied bleaching systems lead to release of small amounts of peroxide into saliva which are not of toxicological concern. There is no difference in peroxide degradation from the different products between smokers and non-smokers. Significantly lowest amounts of peroxide are released from Crest Night Effects. Study granted by Procter&Gamble