In-vitro comparison of in-office physical catalyzed bleaching with at-home techniques

Objectives: To compare the efficacy of three catalytic techniques, combined with 35% and 10% Hydrogen Peroxide for in-office dental bleaching systems and 10% Carbamide Peroxide for at-home bleaching.

Materials and Methods: Lower incisor bovine teeth (n=350) were obtained from the sacrificed bovines for human consumption. All teeth were prepared and random divided into seven groups. Each group received one of the following catalytic sources [Halogen Light (Optilux 501-Demetron), V-LED (Fast Bleach-Cambridge) and Argon Laser (AccueCure-3000-Lasermed)], combined with two commercial bleaching systems, 25% (Zoom, Discus-Dental) and 35% (Polaoffice-SDI). 10% Carbamide Peroxide (PC) (Opalescence-Ultradent) was used as control group. Colour variations were evaluated as ΔE* using a Spectrophotometer with CIELab system®. The data were analyzed using Kruskal-Wallis test, ANOVA and Mann-Whitney Test. Significance was stated at 0.05

Results:

At the beginning, the L-a-b parameters in all groups were homogeneous. After bleaching with all peroxides and light sources used, the L-a-b colour parameters showed a statistically significant (p<0.05) reduction. 35% and 25% HP bleaching systems catalyzed by three sources did not present statistically significant differences (p>0.05). Results of the comparisons between 10% PC and all percentages of HP did not show differences (p>0.05), as well.

Argon Laser showed a lower efficacy (p<0.05) as an activator of bleaching, when compared with Halogen Light, V-Led and At-home techniques.

Conclusions:

Efficacy of In-office catalyzed bleaching was compared with an at-home bleaching technique and no differences were found. Probably, the main indication for the use of light sources in the dental bleaching is efficiency of therapies in terms of time. However, the Argon Laser showed a lower efficacy compared with others catalyzed techniques analyzed. The present results support that bovine teeth are an adequate model for the bleaching techniques.