Avaliação radiográfica e antimicrobiana dos microrganismos Enterococcus faecalis e Actinomyces israelii após Terapia Fotodinâmica (aPDT)

Abstract

Antimicrobial Photodynamic Therapy (aPDT) is an adjunct method to Chemical-Mechanical Preparation (CMP) and an antimicrobial alternative, which may enable the microbicidal effect to reach the most difficult areas of the Root Canal System (RCS). Therefore, this study evaluated the action of aPDT on Enterococcus faecalis and Actinomyces israelii. These microorganisms were identified in samples taken from the RCS, with the aid of absorbent paper cones, in different stages of the proposed treatments using the real Time Polymerase Chain Reaction (PCR) methodology. Twenty-five teeth, anterior and posterior (incisors, canines, and premolars) with a diagnosis of Pulp Necrosis and presence of periapical lesion were randomly selected. These teeth were divided into 2 groups: Group 1 (G1) - Endodontic therapy with PQM and intracanal medication (ICM); Group 2 (G2) - Endodontic therapy with CMP, MIC and 2 applications of aPDT. The aPDT protocol was performed with the application of the 0.005% methylene blue photosensitizer (PS), red light, energy of 9 Joules (J), and wavelength from 400 nm to 660 nm and 90 seconds of application. The samples were processed by Deoxyribonucleic Acid (DNA) extraction. Microorganisms were identified using specific primers. Radiographic monitoring was also performed: initial x-ray and x-ray 60 days after the endodontic treatment ended. The radiographs were evaluated by two examiners, using scores to classify the periapical repair. Enterococcus faecalis was found more frequently in G1 when compared to G2. Actinomyces israelii was found equally in G1 and G2. When the amount of Enterococcus faecalis and Actinomyces israelii was evaluated between collections 1, 2 and 3, it was observed that there was no difference, both in G1 and G2. The statistical analysis of the radiographs was performed first by the Kappa concordance test, which was considered moderate, and afterwards, the G test was performed, verifying that there was no association between the variables group and repair classification. APDT did not promote better results in endodontic treatment, being similar to conventional treatment, however this work pointed out relevant methodological issues. Therefore, new studies are required in order to show the possible effectiveness of aPDT.