Does photodynamic therapy with methylene blue affect the mechanical properties and bond strength of glass-fiber posts in different thirds of intraradicular dentin?

Author(s)

de Oliveira, Murilo Silva ^{[1, 2]} ; da Silva, Paloma Pereira ^{[1, 2]} ; de Melo, Fernanda Santos ^{[1, 2]} ; Teixeira Martinez, Carolina Martins ^{[1, 2]} ; Angelo Cintra, Luciano Tavares ^{[1, 2]} ; Gomes-Filho, Joao Eduardo ^{[1, 2]} ; dos Santos, Paulo Henrique ^[1]

Affiliation

^[1] Sao Paulo State Univ UNESP, Aracatuba Sch Dent, Dept Dent Mat & Prosthodont, Aracatuba, SP - Brazil

^[2] Sao Paulo State Univ UNESP, Aracatuba Sch Dent, Dept Restorat Dent, Discipline Endodont, Aracatuba, SP - Brazil

• Document type: Journal article
• Source: Photodiagnosis and Photodynamic Therapy; v. 30, JUN 2020.
• Web of Science Citations: 1

Abstract

Background: There are few studies on the influence of methylene blue as a photosensitiser on the mechanical properties and adhesion of glass-fiber posts to intraradicular dentin. Thus, this in vitro study aimed to evaluate the influence of photodynamic therapy with a methylene blue photosensitizer on the Martens hardness, elastic modulus, and bond strength of glass-fiber posts in different thirds of intraradicular dentin. Methods: Eighty bovine teeth were divided into the following five groups: a control using deionized water, and four other groups according to the methylene blue concentration (50 mg/L or 100 mg/L) and substrate treatment (with or without red laser action). Ultramicrohardness test was used to evaluate the mechanical properties in different regions of the root dentin (n = 8). Push-out analysis was evaluated using a universal testing machine (n = 8). Data were subjected to the Kruskal-Wallis test, followed by Dunn's test for comparing groups, and the Friedman test for comparing thirds (alpha = 0.05). Representative scanning electron microscopy images were obtained. Results: In general, methylene blue in distinct concentrations, with or without laser action, did not cause differences in the mechanical properties or bond strength in different regions of root dentin (P > 0.05). Methylene blue at a higher concentration, activated with laser, produced lower bond strength values in the middle third of the root canal (P < 0.05). Conclusions: Methylene blue at 50 mg/L had no influence on the mechanical properties of the bovine tooth and the bond strength of the glass-fiber posts to intraradicular dentin. (AU)

• FAPESP's process: 15/06056-3 - Influence of photodynamic therapy on the bond strength of glass fiber posts to radicular dentin
• Grantee: Paloma Pereira da Silva
• Support Opportunities: Scholarships in Brazil - Scientific Initiation