Abstract
OBJECTIVE:
The
aim of this study was to assess the dental bleaching efficacy of 37.5%
hydrogen peroxide (HP), with and without light activation, in HP-exposed
and unexposed areas.
METHOD:
28
bovine teeth were selected and divided into two groups (n = 14). Crowns
were detached and stained with tea. The gingival half was covered with a
gingival barrier. In the incisal half, 37.5% HP (Pola Office+, SDI) was
applied three times, with a 1-week interval between applications. In
HP-A group, the bleaching agent was activated for 3 min with a LED lamp.
No light activation was applied in HP-N group. Dental color variation
was determined through a spectrophotometer in both halves. Statistical
analysis between groups was performed with an ANOVA test, and intragroup
differences were evaluated, with an ANOVA test for paired data, with a
significance level of P < 0.05.
RESULTS:
An
increase in lightness and a decrease in chroma were found in both
groups and halves. No significant differences in ΔE between groups (P
> 0.5) were detected in the incisal half. After treatment, a
significantly higher ΔE was found in the gingival half for HP-A group (P
< 0.05). For the same group, a significantly higher bleaching effect
was found in the gingival half, compared with the incisal half (P <
0.05).
CONCLUSIONS:
LED
activation did not have a significant effect in terms of bleaching in
the incisal half, but increased clearance in the gingival half.
CLINICAL RELEVANCE:
HP
light activation does not significantly increase the whitening effect,
but it can improve the bleaching diffusion to areas where it has not
been directly applied.
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