A randomized CIE-lab evaluation of external bleaching therapy effects on fluorotic enamel stains

Abstract

Objective: To evaluate the effect of external bleaching on the color and luminosity of fluorotic stains and adjacent, normally mineralized enamel areas by means of CIE-(*L,*a,*b) colorimetry.
Materials and Methods: Eighteen adolescents with mild to moderate fluorotic stains were randomly allocated and randomly assigned by lot to either a bleaching group A (n=9) or a control group B. Eligibility criteria were fluorotic stained upper incisors or canines, and the informed consent of the participants and their guardians for taking part in the study. Using a colorimeter, CIE-(*L,*a,*b) -values of maxillary incisors and canines were assessed at baseline (T1) in the center of the fluorotic stained area (F1) and at adjacent, normally mineralized enamel areas (F2). Then, external bleaching with
Illuminé office (30% H2O2, Dentsply DeTrey) was carried out for 60 min, followed by color reassessment (T2). 14 days after (T3), a two-week home bleaching period with a daily bleaching time of 1h with Illuminé home (15% Carbamide Peroxid, Dentsply DeTrey) was conducted with subsequent
color determination (T4).
Results: After completion of bleaching therapy, 96% of all fluorotic areas F1 and 100% of area F2 showed a significant change within group A, and 29.4% in control group B. Comparing the collective ΔE (L*,a*, B*) of F1 and F2, 60% of all areas showed significant differences after completion of bleaching therapy, in comparison to 88% initial. 82.4% of Group B sites showed colour differences in
the beginning (T1) and 88.2% at the end (T4).
Conclusion: Whereas a single session of 1 hour in-office bleaching with 30% H2O2 does not significantly affect the colour and luminosity of fluorotic teeth, a 14 day period of home bleaching leads to an assimilation of the fluorotic stains’ colour with the colour of surrounding enamel areas due to different responses of sound and fluorotic enamel to the bleaching regime.