Effect of halogen light irradiation on hydrogen peroxide bleaching: an in vitro study

Abstract

Background: The aim of this study was to evaluate the effect of halogen light irradiation on hydrogen peroxide (HP) bleaching by assessing HP concentrations, tooth whitening efficacy, and temperature variations in bleaching agents and pulp chambers. Methods: Sixteen premolars were randomly divided into two groups: Group BL (bleaching agent with halogen light irradiation for 3 · 10 minutes) and Group B (bleaching agent alone). HP concentrations were tested before and after treatment. CIE L*a*b* values of specimens were obtained using a spectrophotometer. Temperatures of bleaching gels and pulpal chambers were recorded by a digital multimeter with K-type thermocouple. Data were analysed using ANOVA and paired t-test. Results: After treatment, HP concentration in group BL was slightly higher than that in group B. Paired t-tests revealed significant differences of DE between groups BL and B in all time intervals except at day 35. The temperature rise of bleaching gels and pulpal chambers in group BL was significantly higher than that in group B. Conclusions: In-office bleaching was effective for tooth whitening. The involvement of halogen light was beneficial for the immediate whitening effect but had little impact on the long-term whitening effect.

Evaluation of two types of bleaching gel and light source on whitening of teeth

“…So in both of these study groups, teeth were exposed longer to QTH light. Relapse in treatmentin the Polydorous study only occurred in a month after treatment QTH group (Polydorou et al, 2013), which is similar to the results of our study, while both groups in the Liangs study showed relapse after a week with or without light cure system (Liang et al, 2012).…”

“…For other groupsin the Polydorous study, relapse occurred after 3 months (Polydorou et al, 2013), while in Liangs it happened sooner (Liang et al, 2012). These results can be explained by a lower concentration of bleaching agent used in study (32% Beyond II Advanced Formula Whitening Gel) compared with current study (37.5% Polaoffi ce and 40% Opalescence Boost) and Polydorou study (38% Opalescence Boost), although this difference is negligible.…”

“…QTH produce more heat than light on the tooth surface which can form groups that cause more tooth dehydration (Liang et al, 2012). Also, previous studies which have examined different types of light reported that QTH effect was remarkably higher in immediately after bleaching (Sulieman et al, 2005Liang et al, 2012. Table 1.…”

“…In the present study, the Tukey test results showed that in both bleaching agent (Opalescence and Pola offi ce), QTH Light application signifi cantly increased the effectiveness of bleaching component compared to LED or without light, immediately after bleaching teeth, 3 days and 7 days after bleaching, Because QTH heat transfer capability to the teeth is more than LED. QTH produce more heat than light on the tooth surface which can form groups that cause more tooth dehydration (Liang et al, 2012). Also, previous studies which have examined different types of light reported that QTH effect was remarkably higher in immediately after bleaching (Sulieman et al, 2005Liang et al, 2012.…”

“…Although, in this study QTH had greater effectiveness after 7 days, but after one month treatment relapse was observed. In Polydorous study, the use of QTH for each tooth was 4times in 8 minutes (Polydorou et al, 2013), while in Liangs study, two sessions with7 days interval 3 times of 10 minute were applied (Liang et al, 2012). So in both of these study groups, teeth were exposed longer to QTH light.…”