Influence of violet LED associated or not with peroxide gel on inflammation, mineralization, and collagen fiber maturation in dentin and pulp tissue

• Published in: Photodiagnosis and photodynamic therapy 2022-09, Vol.39, p.102959-102959, Article 102959
• Main Authors: da Silva, Livia Maria Alves Valentim, Cintra, Luciano Tavares Angelo, de Alcântara, Sibele, Machado, Nathália Evelyn da Silva, Benetti, Francine, Ervolino, Edilson, Briso, André Luiz Fraga
• Format: Article
• Language: English
• Subjects: Bleaching; Collagen; Inflammation; Violet LED
• ISSN: 1572-1000; 1873-1597
• DOI: 10.1016/j.pdpdt.2022.102959

•Violet LED does not generate inflammation and fibrosis in the pulp tissue.•Association of light with a less concentrated gel can make your teeth more sensitive.•Violet LED only affects the most superficial layers of dental tissue, such as dentin.•Light did not accelerate the maturation of collagen fibers in the pulp even with gel. To evaluate the influence of violet LED, associated or not with a 17.5% hydrogen peroxide (HP) bleaching gel, on inflammation, mineralization in pulp tissue, and collagen fiber maturation in dentin and pulp tissue. The maxillary molars of eighty Wistar rats were distributed into four groups (n = 10): CONT – without treatment; HP – 30 min application of 17.5% HP; LED – 20 min application of violet LED; and HP+LED – application of PH and violet LED. Rats were euthanized and jaws were processed for histologic and immunohistochemical evaluation (IL-17, IL-23, and osteocalcin) and picrosirius red immediately after (T0), and at 7 (T1), 15 (T2), and 30 days (T3) post-treatment, with Wilcoxon, Mann-Whitney, paired T-test, and T-test (α = 0.05). HP and HP+LED presented necrosis and severe inflammatory infiltrate. When compared to CONT group, LED presented severe osteocalcin (OCN) immunostaining in T2 and less immature fibers in T2 and T3. The violet LED caused no severe damage to the pulp tissue, increased IL-17 and IL-23 expression in T0 when associated with HP, and had no influence on pulp tissue mineralization, besides accelerating the maturation of collagen fibers of dentin. Clinical relevance: Violet LED therapy induced no inflammation in the pulp tissue of rats and played no role in pulp tissue fibrosis, besides accelerating the maturation of dentin collagen fibers.