In vitro colorimetric evaluation of the efficacy of various bleaching methods and products

Abstract

<h3>Objective</h3> Various bleaching modalities are now offered to patients, either monitored by the dental office or self-directed, for which relative efficacy is unknown. The aim of this in vitro study was to evaluate the ability of different bleaching products and protocols to lighten enamel and dentin. <h3>Method and Materials</h3> Bovine tooth samples of standardized thickness (2.5 ± 0.025 mm with similar dentin and enamel thicknesses) were prepared and stained with whole blood and hemolysate before being submitted to 11 different bleaching regimens: home bleaching using 10%, 15%, 16%, or 20% carbamide peroxide, power bleaching using 15% hydrogen peroxide, 30% hydrogen peroxide, or 25% carbamide peroxide with or without light activation, and over-the-counter bleaching strips containing 5.3% hydrogen peroxide. Colorimetric measurements were performed on each sample side, according to the CIE L^{∗^a∗}b^∗ system, before and after staining as well as after each series of 5 bleaching sessions (number of applications varied from 5 to 20 times, according to the bleaching protocol). <h3>Results</h3> All products and protocols produced a similar bleaching effect on enamel, while the home bleaching regimen proved largely superior to lighten dentin. <h3>Conclusion</h3> In-office bleaching techniques proved less efficient than home bleaching for removing stains deposited in dentin.—<i>Reprinted with permission of Quintessence Publishing</i>.