Bleaching effect of ozone on pigmented teeth

Abstract

Background: There have been numerous researches on ozone application in dentistry; yet the

data regarding its whitening effect is very limited. The present study compares the bleaching effect

of ozone with offi ce bleaching.

Materials and Methods: In this experimental study, 15 maxillary premolar teeth were selected

and sectioned mesio-distally and bucco-lingually. The sections were then placed in tea for 1 week

according to the Sulieman method and were divided into three groups each comprised of 15

sections. The samples were bleached as followed; Group I: Bleached with 35% hydrogen peroxide

in three intervals of 8 min each, Group II: Underwent ozone treatment using Ozotop unite for 4

min and Group III: Bleached with a combination of both methods. The color indices of the samples,

i.e., (a) green-red pigment, (b) blue-yellow pigment, (L) brightness, (ΔE) overall color change, were

evaluated pre- and post-bleaching utilizing a digital camera, Photoshop software and CIE lab index.

The color changes of specimens then were calculated and analyzed through randomized analysis

of variance and Tukey tests. P < 0.001 was considered to be signifi cant.

Results: The color change (ΔE) in Group II was signifi cantly lower than those in the two other groups

(P < 0.001). There was no signifi cant difference between the color change of Groups I and III (P = 0.639).

In addition, the results of L, a and b brought forth a similar pattern to the fi ndings obtained from ΔE.

Conclusion: The hydrogen peroxide gel has a more powerful whitening effect than ozone; in

addition, ozone has no synergistic effect when is used simultaneously with hydrogen peroxide.

Key Words: Hydrogen peroxide, ozone, tooth bleaching