Fracture resistance and bonding performance after antioxidants pre-treatment in non-vital and bleached teeth.

This study aimed to evaluate the effect of antioxidant solutions on fracture strength and bonding performance in non-vital and bleached (38% hydrogen peroxide) teeth. One hundred and eighty dentin specimens were obtained, 60 for each test: fracture strength, hybrid layer thickness, and bond strength. The groups (n=10) were randomly composed according to post-bleaching protocol: REST - restoration, without bleaching; BL - bleaching + restoration; SA - bleaching, 10% sodium ascorbate solution, and restoration; AT - bleaching, 10% α-tocopherol solution, and restoration; CRAN - bleaching, 5% cranberry solution, and restoration; CAP - bleaching, 0.0025% capsaicin solution, and restoration. Data were analyzed with ANOVA, Kruskal-Wallis, Dunn, and Qui-Square tests (α=0.05). The highest fracture strength values were observed in REST (1508.96 ±148.15 N), without significant difference for the bleached groups (p>0.05), regardless of the antioxidant use. The hybrid layer thickness in the group that was not subjected to bleaching (REST) was significantly higher than in any other group. The bond strength in the bleached and antioxidants-treated groups (SA, AT, CRAN, CAP) has no differences with the bleached group without antioxidants (BL). Adhesive failures were predominant in the groups that did not receive the antioxidant application. In conclusion, the evaluated antioxidants did not show an effect on the fracture strength, hybrid layer thickness, or bond strength of dentin bleached after endodontic treatment. The application of 10% sodium ascorbate, 10% alpha-tocopherol, 5% cranberry, or 0.0025% capsaicin solutions is not an effective step and should not be considered for the restorative protocols after non-vital bleaching.

The effect of photobiomodulation using low-level laser therapy on tooth sensitivity after dental bleaching: a systematic review.

The authors aimed to conduct a systematic review to assess data from the current literature on the effectiveness of low-level laser therapy (LLLT) in preventing tooth sensitivity (TS) after tooth whitening (DB). PRISMA guidelines for systematic reviews were followed. Clinical trials evaluating the treatment of LLLT in patients with sensitivity after tooth whitening were selected. A full bibliographic search was performed on May 4, 2021, in the following databases: Embase, MEDLINE via PubMed, SciELO, VHL Regional Portal, Web of Science, Gray Literature, Scopus, ClinicalTrials.gov and Cochrane Library. This study followed Cochrane's recommendations for analyzing risk of bias. A total of 1054 studies were found (255 studies were excluded because they were duplicates and 785 because of titles and abstracts). Only 14 articles were selected for analysis, of which eight were excluded because they had one or more exclusion criteria, resulting in six articles included in this systematic review, the vast majority being classified as low risk of bias. The studies reviewed indicated that LLLT showed promise in preventing TS after TB. However, evidence is limited and more clinical trials with low risk of bias are needed to reach a definitive conclusion on the action of LLLT in pain control after TB.