Abstract
The clinical efficacy regarding bleaching sensitivity and tooth shade lightening using a standard hydrogen peroxide (H
O
) bleaching gel was compared with the additional use of ozone either before or after application of H
O
. Using computer-generated tables, 45 participants were randomly allocated into three groups (n = 15 each) in this investigator-driven, single-centre trial. In Group 1, upper anterior teeth were bleached using ozone (produced via a healOzone X4 device) for 60 seconds, then 38% H
O
for 20 minutes; in Group 2, 38% H
O
application (20 min) was followed by ozone (60 s); air produced by the healOzone machine (60 s) followed by 38% H
O
(20 min) was used in Group 3 (control). Bleaching sensitivity was evaluated via visual analogue scales, and a treatment-blinded reader objectively recorded tooth shades using a colorimeter before and 24 hours after bleaching (at α = 0.05). The H
O
/ozone combination did not result in pain sensations, while both ozone/H
O
and H
O
alone increased bleaching sensitivity (p < 0.001). Teeth achieved lighter shades (higher L*/lower b* values) after bleaching in all groups (p < 0.001), while Ozone boosted lighter tooth shades, irrespective of its use before or after H
O
(p < 0.05). Due to the complimentary effects, applying ozone after H
O
seems preferable for bleaching.