• lovesharon91 posted an update 2 weeks, 1 day ago

    The root opening was then sealed with wax. Statistical analyses were performed using SPSS 16.0 (SPSS, Chicago, IL, USA). Descriptive statistics were obtained, and data were reported as mean ± SD. The colour differences in each group were analysed using a one-way repeated measure of analysis of variance (ANOVA) to evaluate the within-group factor (time). Paired t-test was used to analyse the colour change values between the two groups. The changes in HP concentration were analysed using one-way ANOVA. The maximal temperature rise (ΔT) was analysed with paired t-test and Pearson’s correlation test. All analyses were followed by Tukey’s post hoc test for multiple comparisons (α = 0.05). The pH value of activated gels Alectinib manufacturer was 4.00 ± 0.05. After bleaching, the mean HP concentration in group BL was slightly higher than that in group B (p = 0.027), but they were not different from baseline (p = 0.278, p = 0.497, respectively) (Fig. 3). The irradiated area of the halogen lamp was 65 mm × 25 mm, and its output ranged from 390 to 740 nm (purple, blue and green), with a major peak at 530 nm (green) and a minor peak at 662 nm (red). Colour coordinates (ΔL*, Δa* and Δb*) and ΔE for each testing interval are shown in Fig. 4. The whitening treatments resulted in increased L* and ΔE and decreased b*. After treatment, colour relapse was found in each group, especially in group BL. One-way repeated measure of ANOVA revealed that ΔE, ΔL*, Δa* and Δb* were significantly influenced by time (all p < 0.001). Tukey’s post hoc comparison results of ΔE are listed in Table 1. The maximal value of ΔE was detected after the second treatment. The two groups had statistically different Δb* and ΔE (all p < 0.001), but not for ΔL* and Δa* (p = 0.435, p = 0.135, respectively). Paired t-tests revealed highly significant differences in ΔE between the two groups in all intervals except day 35 (p = 0.201 for day 35). The representive temperature curves of bleaching gels during treatment for each cycle are shown in Fig. 5, and the intrapulpal temperature variation is given in Fig. 6. ΔT (means ± SD) for bleaching gels and pulpal chambers are described in Table 2. Light irradiation induced a significantly higher temperature increase in both bleaching gels and pulpal chambers (p < 0.001). Pearson correlation coefficient of ΔT between bleaching gels and pulpal chambers in each group was 0.831, and the degree of correlation was pole strength. The present study indicated that tooth whitening could be achieved with a highly concentrated bleaching agent with and without light activation. Moreover, in-office bleaching with halogen light irradiation was more effective to improve the immediate tooth whitening than unirradiated treatment. These results were in agreement with previous studies that used different types of light sources.