|
Aware of the diffusion capacity of bleaching in the dental tissues, many orthodontists are subjecting their patients
to dental bleaching during orthodontic treatment for esthetic purposes or to anticipate the exchange of esthetic
restorations after the orthodontic treatment. For this purpose specific products have been developed in pre-loaded
whitening trays designed to fit over and around brackets and wires, with clinical efficacy proven. Objective: The
objective of this study was to evaluate, through spectrophotometric reflectance, the effectiveness of dental blea
-
ching under orthodontic bracket. Material and methods: Thirty-two bovine incisors crown blocks of 8 mm x 8 mm
height lengths were used. Staining of tooth blocks with black tea was performed for six days. They were distributed
randomly into 4 groups (1-home bleaching with bracket, 2- home bleaching without bracket, 3- office bleaching
with bracket, 4 office bleaching without bracket). The color evaluation was performed (CIE L * a * b *) using
color reflectance spectrophotometer. Metal brackets were bonded in groups 1 and 3. The groups 1 and 2 samples
were subjected to the carbamide peroxide at 15%, 4 hours daily for 21 days. Groups 3 and 4 were subjected to 3
in-office bleaching treatment sessions, hydrogen peroxide 38%. After removal of the brackets, the second color
evaluation was performed in tooth block, difference between the area under the bracket and around it, and after 7
days to verified color stability. Data analysis was performed using the paired t-test and two-way variance analysis
and Tukey's. Results: The home bleaching technique proved to be more effective compared to the office bleaching.
There was a significant difference between the margin and center color values of the specimens that were subjected
to bracket bonding. Conclusions: The bracket bond presence affected the effectiveness of both the home and office
bleaching treatments.
|