Hydrogen Peroxide: A Review of Its Use in Dentistry

Abstract

Several dentifrices that contain hydrogen peroxide are currently being marketed. The increased use of bleaching agents containing (or generating) H2O2 prompted this review of the safety of H2O2 when used in oral hygiene. Daily exposure to the low levels of H2O2 present in dentifrices is much lower than that of bleaching agents that contain or produce high levels of H2O2 for an extended period of time. Hydrogen peroxide has been used in dentistry alone or in combination with salts for over 70 years. Studies in which 3% H2O2 or less were used daily for up to 6 years showed occasional transitory irritant effects only in a small number of subjects with preexisting ulceration, or when high levels of salt solutions were concurrently administered. In contrast, bleaching agents that employ or generate high levels of H2O2 or organic peroxides can produce' localized oral toxicity following sustained exposure if mishandled. Potential health concerns related to prolonged hydrogen peroxide use have been raised, based on animal studies. From a single study using the hamster cheek pouch model, 30% H2O2 was referred to as a cocarcinogen in the oral mucosa. This (and later) studies have shown that at 3% or less, no cocarcinogenic activity or adverse effects were observed in the hamster cheek pouch following lengthy exposure to H2O2. In patients, prolonged use of hydrogen peroxide decreased plaque and gingivitis indices. However, therapeutic delivery of H2O2 to prevent periodontal disease required mechanical access to subgingival pockets. Furthermore, wound healing following gingival surgery was enhanced due to the antimicrobial effects of topically administered hydrogen peroxide. For most subjects, beneficial effects were seen with H2O2 levels above 1%. J Periodontol 1995;66:786–796.

Safety issues relating to the use of hydrogen peroxide in dentistry

“…Their study used hamsters in which the buccal pouches were painted with 3 per cent or 30 per cent hydrogen peroxide solution twice weekly for 19 to 22 weeks, while DMBA was applied twice weekly on days other than when the hydrogen peroxide was applied. However, as pointed out subsequently by Marshall et al, 5 the results of the Weitzman study are of marginal or no statistical significance because of the small number of animals utilized, and the weak effect observed even at the highest concentration of hydrogen peroxide. No differences were observed between control and experimental groups after 19 weeks.…”

“…Furthermore, administration of 70mg/kg hydrogen peroxide per day for up to six months did not increase bone marrow sister chromatid exchange in Chinese hamsters. 5 Genotoxicity was also not seen in the TA102 strain with 267mmol/l hydrogen peroxide incorporated into a dentifrice. This may be explained in part by the presence of oxidant-trapping agents such as sorbitol in the dentifrice.…”

“…Thus, results from any laboratory tissue culture systems which use a medium containing histidine should be interpreted with caution. 5 Finally, while hydrogen peroxide itself has been shown to be genotoxic in an oxidant-sensitive tester strain of the bacterium Salmonella typhimurium (strain TA102), extensive testing has revealed that a hydrogen peroxide-generating tooth bleaching agent is neither genotoxic in this strain nor in mammalian cells. Furthermore, administration of 70mg/kg hydrogen peroxide per day for up to six months did not increase bone marrow sister chromatid exchange in Chinese hamsters.…”

Can Whitening Strips interfere with the Bond Strength of Composite Resins?

“…In contact with the enamel surface, hydrogen peroxide decomposes into water and oxygen, which diffuse through the enamel and oxidize organic pigments, thus reducing the number of dark pigments. 8 Impaired bond strength is mainly associated with the presence of residual oxygen within the tooth structure. Scanning electron microscopy (SEM) and fracture resistance tests indicate that the reduction of the bond strength might be associated with impaired resin ability to attack hydrogen peroxide-treated surfaces.…”

Letter to the Editor

“…[1][2][3][4][5][6][7][8][10][11][12][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] For several reasons the above assumption is not valid.…”