Influência da terapia fotodinâmica com azul de metileno na dentina radicular: estudo das propriedades mecânicas (dureza e módulo de elasticidade)

• Autor(a) principal: Oliveira, Murilo Silva de [UNESP]
• Data de Publicação: 2017
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/156738; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2018-06-12/000901917.pdf
• topic: Tratamento do canal radicular; Fotoquimioterapia; Azul de Metileno; Dureza; Módulo de elasticidade; Root canal therapy

Through the past years, strong evidence has demonstrated the success of photodynamic therapy (PDT) in decreasing the microbial load. However, there are no studies concerning the influence of PDT on the mechanical properties of root dentin. The PDT is based on a set of physical, chemical and biological procedures that occur after administration of a specific wavelength-activated photosensitizing agent (FS), with the objective of destroying specific cells. The aim of the present study was to evaluate the influence of PDT on root dentin using the methylene blue FS (MPS), analyzing the dentin mechanical properties (hardness and elastic modulus). Forty bovine teeth were used in this study, initially radiographed in order to confirm the integrity of the entire dental structure. The crown was cut 1 mm above the cement-enamel junction and the root canal biomechanical preparation was performed with the aid of a surgical bur nº 703 in the crown-apex direction and vice versa. After the final irrigation with 1% sodium hypochlorite, the root canals were aspirated with endodontic cannulas and dried with sterile absorbent paper cones #80. Then, distributed in 5 groups (n = 8) according to the FS used: G1- Deionized water (control); G2-FS methylene blue 0.005%; G3- FS methylene blue 0.005% + 660nm red laser (TFD) 1 minute; G4-FS methylene blue 0.01%; G5- FS methylene blue 0.01% + 660nm red laser (TFD) 1 minute. A flexible optical fiber of 300 μm diameter was used, until 2 mm before the working length (WL) in G3 and G5. All 4 groups (G2 to G5) received methylene blue FS for 3 minutes (pre-irradiation period), agitated for 60 seconds with ultrasound (passive irrigation - no refrigeration) with the power scale for Endodontics set as 2, using a K #25 file also 2mm before the WL. Afterwards, the specimens were cut perpendicularly to the long axis, with a diamond disk on an Isomet 2000 precision cutter, obtaining a slice...