Long-term efficacy of in-office and at-home bleaching: a 2-year double-blind randomized clinical trial.
OBJECTIVE
This parallel, double-blind randomized clinical trial evaluated the 2-year bleaching efficacy and sensitivity produced by at-home (AH) and in-office (IO) bleaching therapies.


METHODS
60 participants with tooth color darker than C2, without restorations in the anterior dentition and older than 18 years old, were randomly allocated into two groups to receive either IO with 35% hydrogen peroxide or AH with 16% carbamide peroxide. Color was recorded at baseline (BA); 1-week (1W); end of the treatment (ET); and 2 years (2Y) after bleaching, using the Vita Classical shade guide. The perception of TS was recorded on a 0-4 scale during and 2Y after bleaching. The variation in shade guide units (deltaSGU) from BA vs. 1W was compared to deltaSGU from BA vs. 2Y using paired t-test. The percentage of subjects who reported TS was evaluated by Fisher's exact test. The intensity of TS was evaluated by a Mann-Whitney test (alpha=0.05).


RESULTS
Both bleaching techniques demonstrated equivalent and significant tooth color shade lightening. No significant color rebound occurred after 2Y for both techniques (P= 0.77 and 0.87, for AH and IO respectively). The absolute risk of TS was similar for IO and AH (P= 0.12), however the intensity of TS was significantly higher for IO (P= 0.001). No subjects reported sensitivity after 2Y.
Department of Restorative Dentistry, School of Dentistry, State University of Ponta Grossa, Paraná, Brazil.
Lidia Yileng
LY
Tay
Carlos
C
Kose
Daniel Rodrigo
DR
Herrera
Alessandra
A
Reis
Alessandro Dourado
AD
Loguercio
D000077463:Carbamide Peroxide; D003807:Dentin Sensitivity / Q000139:chemically induced; D004311:Double-Blind Method; D005260:Female; D006699:Home Care Services; D006801:Humans; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D009819:Office Visits; D010545:Peroxides / Q000008:administration & dosage / Q000009:adverse effects; D018709:Statistics, Nonparametric; D014073:Tooth Bleaching; D058205:Tooth Bleaching Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D014075:Tooth Discoloration / Q000188:drug therapy; D014508:Urea / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D055815:Young Adult
D010545:Peroxides; D058205:Tooth Bleaching Agents; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide