Bond strength of glass fiber posts to radicular dentin submitted to two sessions of photodynamic therapy

• Grant number: 16/24718-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2017
• Effective date (End): December 31, 2017
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Gustavo Sivieri de Araújo
• Grantee: Paloma Pereira da Silva
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

Photodynamic therapy (PDT) is based on physical, chemical and biological processes that occur after the use of a photosensitizer (PS) which is active by visible light, with a specific wavelength, to aim to destroy the target cells. Actually, strong evidences show the efficacy on microorganism reduction promotes by PDT, potentiating root canal instrumentation. However, the risk of contamination of the pulp cavity after the preparation of the intraradicular posts and before definitive cementation of the same may occur. Therefore, the use of the second session PDT for decontamination of the pulp cavity becomes interesting. However, there are not studies of the effect of PDT (two sessions) on the mechanical properties of radicular dentin. The aim of the present study will be to evaluate the effect of PDT in two sessions on the bond strength of glass fiber posts in different thirds of the radicular dentin (cervical, middle and apical), through the push-out test. For this study forty freshly extracted bovine incisors will be used. The biomechanical preparation in all root canals with K file, which the final instrument a K #70, 1 mm short of root apex and irrigation with 1% sodium hypochlorite. To perform the PDT (1st session), the PS methylene blue activated with red laser 660nm will be used, helped by an optical fiber with a 500µm diameter length positioned 2mm before the working length. All teeth were filled with gutta-percha and root-canal sealer. The root canals will be prepared to receive the glass fiber posts. Subsequently, PDT (2nd session) will be performed again, following the protocol mentioned above. Then all root canals will be dried and will be prepared for receive glass fiber posts and will be cemented into to the root canal with self-adhesive resin cement. The bond strength will be measured using the push-out test in a universal assay machine on the three parts of intracanal dentin (cervical, middle and apical). The data will be submitted to normality test and the means will be compared by specific statistical tests (±=0.05). Representative samples of each group will be analyzed with scanning electron microscopy. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

STRAZZI-SAHYON, HENRICO BADAOUI; DA SILVA, PALOMA PEREIRA; NAKAO, JAQUELINE MIDORI; DA SILVA, PATRICIA ZAMBON; NUNES, LARISSA PEREIRA; SERON, MARCELO AUGUSTO; ANGELO CINTRA, LUCIANO TAVARES; DOS SANTOS, PAULO HENRIQUE; SIVIERI-ARAUJO, GUSTAVO. Influence of two photodynamic therapy sessions and different photosensitizers on the bond strength of glass -fiber posts in different regions of intraradicular dentin. Photodiagnosis and Photodynamic Therapy, v. 33, MAR 2021. (16/24718-6)