The impact of methylene blue photosensitizer, aPDT and a calcium hydroxide-based paste on the physicochemical and mechanical characteristics of root canal dentin and the bonding interface of fiberglass posts

• Published in: Journal of photochemistry and photobiology. B, Biology Biology, 2024-04, Vol.253, p.112878-112878, Article 112878
• Main Authors: Strazzi-Sahyon, Henrico Badaoui, Banci, Henrique Augusto, Maltarollo, Thalya Fernanda Horsth, Martinez, Carolina Martins Teixeira, Rocha, Eloísa Alexo, Figueiredo, Roberto Braga, Garcia, Dayana Cristina Silva, Constantino, Carlos José Leopoldo, Spin-Neto, Rubens, Duarte, Marco Antonio Hungaro, Cintra, Luciano Tavares Angelo, dos Santos, Paulo Henrique, Sivieri-Araujo, Gustavo
• Format: Article
• Language: English
• Subjects: Animals; Anti-Infective Agents; biomechanics; calcium; Calcium hydroxide; Calcium Hydroxide - pharmacology; Cattle; cement; chemical structure; Degree of conversion; Dental Pulp Cavity; Dentin; disinfection; fiberglass; Glass; glass fibers; irradiation; irrigation; Materials Testing; Mechanical properties; Methylene blue; Methylene Blue - pharmacology; modulus of elasticity; photobiology; photochemistry; photochemotherapy; Photochemotherapy - methods; Photodynamic therapy; photosensitivity; photosensitizing agents; Photosensitizing Agents - pharmacology; Water
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2024.112878

To investigate the influence of methylene blue (MB)-mediated antimicrobial photodynamic therapy (aPDT) and calcium hydroxide (CH) medication on the mechanical characteristics, degree of conversion (DC), quantification, and volume of gaps at the adhesive interface of glass fiber posts (GFPs) luted to distinct thirds of root canal dentin. Additionally, the microhardness (MH), elastic modulus (Eit), morphology, and chemical structure of the intraradicular dentin were assessed. 6 experimental groups were formed by sorting 102 bovine incisors. Canals receiving deionized water irrigation as a negative control; canals receiving deionized water irrigation and filled with CH as a positive control; groups treated with CH + MB at 50 and 100 mg/L without irradiation; and groups treated with CH + MB at 50 and 100 mg/L irradiated by red laser for 60 s (660 nm; 100 mW; 6.5 J; 72 J/cm2). MH, Eit, and DC properties were evaluated for both the resin cement layer and root dentin substrate (n = 8). Volume and quantification of gaps at the bonding interface (n = 6), and dentin morphology and chemical content were investigated (n = 3). Data were analyzed using a repeated-measures 2-way ANOVA followed by Tukey post hoc analysis (α = 0.05). The distinct intraradicular thirds and treatment with MB-mediated aPDT, whether activated or not, in combination with CH, had a significant impact on the mechanical characteristics of the root dentin. This effect was also observed in the MH, Eit, DC, quantification, and volume of gaps at the luting interface (P