Abstract
Aim: The present study aimed to assess in vitro the effect ofviolet LED in tooth bleaching techniques associated or not withlow-concentration hydrogen peroxide gel on enamel surfaceroughness. Methods: Fifty-two enamel fragments of bovineteeth were flattened and polished (4x4x3 mm) and dividedinto four groups according to bleaching treatment: VL- VioletLED; HP- 7.5% hydrogen peroxide; HP+VL- 7.5% hydrogenperoxide + violet LED; C- No bleaching (control). Before thetreatments, all specimens were immersed in 20 mL of blacktea for six days, changing solutions every 24 h to simulatethe staining of specimens. Forty fragments were used toanalyze surface roughness (n=10) and 12 fragments wereused for the morphological analysis (SEM) (n=3). Results:The data were submitted to one-way ANOVA and a post-hocTukey test. The lower roughness values was observed for thegroup that did not receive bleaching treatment (C), differingsignificantly only from the group bleached with 7.5% hydrogenperoxide + violet LED (HP+VL) (p=0.0077). The remaininggroups did not show significant differences in roughnessvalues (p>0.05). The scanning electron microscopy analysisshowed irregularities on the enamel surface regardless ofthe treatment received. Conclusion: The results showedthat bleaching treatments with violet LED associated withlow-concentration hydrogen peroxide gels (7.5%) increasethe surface roughness of tooth enamel.
Highlights
The most common bleaching process is the application of carbamide peroxide or hydrogen peroxide gel on tooth enamel[1,2], using techniques performed in-office or at home by the patient
Lower roughness values for the group that did not receive bleaching treatment (C) was observed, differing significantly only from the group bleached with 7.5% hydrogen peroxide + violet LED (HP+VL) (p=0.0077)
All groups showed an increase in average surface roughness values (Ra) when compared to the initial surface roughness values
Summary
The most common bleaching process is the application of carbamide peroxide or hydrogen peroxide gel on tooth enamel[1,2], using techniques performed in-office or at home by the patient. Light sources are often used in association with gels to accelerate the decomposition of peroxides, but they may increase the temperature of the tooth structure depending on the light source used[4] These tooth bleaching techniques show to be effective as a color change, but in many cases, it can cause tooth sensitivity[2]. They are seen in the literature some unwanted effects on the enamel structure related to peroxide gels and some associated light sources, among which are roughness increase, hardness decrease, and surface morphology changes[5,6]. Such changes may be harmful to patients because of the increase in enamel porosity, facilitating the adhesion of microorganisms[7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
