The whitening effect of chlorine dioxide—An in vitro study

Journal of Dentistry

Available online 23 May 2013

Abstract

Objectives

The aim of this study was to investigate the whitening properties and rate of bleaching action of chlorine dioxide and compare them with those of hydrogen peroxide of similar concentration.

Methods

Sixty bovine central incisor crowns were ground and polished until flat surfaces were obtained. The crowns were subjected to extensive staining cycles of artificial saliva, chlorehexidine and tea before being randomly assigned to three groups: chlorine dioxide (ClO₂), hydrogen peroxide (H₂O₂) and deionised water (H₂O). The crowns in each group were subjected to seven 2 min exposure cycles in addition to an extra 30 min cycle. CIE LAB spectrophotometric measurements were taken at baseline, after each 2 min, and each extended 30 min bleaching cycle.

Results

L* for ClO₂ specimens was significantly higher only after the first 2 min cycle (p < 0.001) while for H₂O₂ specimens, L* significantly increased after the first two cycles (p < 0.001) and continued to increase, at a slower rate, until the end of the treatment cycles. ΔE was significantly greater within H₂O₂ than within ClO₂ specimens (p < 0.001).

Conclusion

Chlorine dioxide whitens teeth at a faster rate than hydrogen peroxide. Specimens treated with chlorine dioxide were significantly lighter than those treated with hydrogen peroxide at the end of the first 2 min application cycle, however, extended exposures did not enhance colour.