Effect of At-Home Versus Over-the-Counter Bleaching Agents on Enamel Color, Roughness, and Color Stability

Abstract

Background This study was designed to evaluate the efficacy of standard at-home bleaching agents in comparison to new over-the-counter (OTC) products on human enamel regarding color change, color stability, and surface roughness. Methodology A total of 80 extracted adult human maxillary central incisors were prepared and arbitrarily divided into the following four equal groups (N =20): group A: at-home opalescence boost containing 15% carbamide peroxide (CP); group B: crest whitening strips containing 6% hydrogen peroxide (HP); group C: light-emitted diode (LED) home tray with 20% CP + 4% HP; and group D: white and black toothpaste containing active charcoal components. Tooth color was measured using a spectrophotometer. Enamel surface roughness using a three-dimensional optical profilometer was measured before and after the bleaching procedure. To assess color stability, each bleached group was further subdivided into two equal subgroups (n = 10) according to the immersion media of either coffee or tea. Finally, the color was measured after 24 hours of immersion. Results All groups showed improvement in color from the baseline. The crest whitening strips group showed the lowest color improvement in comparison to all other groups. After staining, group C showed the lowest mean color change value ∆E2. No statistically significant difference was noted in surface roughness among all groups. Conclusions All OTC bleaching products as well as at-home bleaching improve teeth color and increase roughness on the enamel surface. Staining media has an adverse effect on the teeth after bleaching. The LED home tray showed a better whitening effect and color stability after bleaching.

Keywords: at-home bleaching; carbamide peroxide; color stability; hydrogen peroxide; over-the-counter products; surface roughness; tooth bleaching.

Figure 1. Illustration of the study design.

CP = carbamide peroxide; HP = hydrogen peroxide

Figure 2. Bar chart representing mean values of ΔE1 after bleaching for different groups

Figure 3. Bar chart representing ∆E2 comparison between each group in tea and coffee staining mediums.

Figure 4. Surface roughness before and after different bleaching treatments using a three-dimensional optical profilometer.

Three-dimensional optical profilometer images before and after the application of bleaching gels. Group A: opalescence boost containing 15% carbamide peroxide, group B: crest whitening strips containing 6% hydrogen peroxide, group C: a light-emitted diode home tray with 20% carbamide peroxide + 4% hydrogen peroxide, and group D: white and black toothpaste containing active charcoal components.

Figure 5. Bar chart representing roughness for different groups before and after bleaching.