Avaliação in vitro das alterações morfológicas e infiltração apical de dentes tratados endodonticamente associados à terapia fotodinâmica

Abstract

The antimicrobial PDT is an eficient method supporting the disinfection of the root canal system, which makes it important to study on the possibility of morphological and permeability caused by the diode laser on the root dentin structure. The purpose of this study was to investigate the morphological and percentage of root apical leakage after using the diode laser. Forty single teeth were instrumented by Protaper rotary system and irrigated with 5.25% NaOCl and 17% EDTA. They were then randomly divided into: G1 not receive PDT (control), G2: received pre-irradiation with toluidine blue photosensitizer and irradiation by GaAlAs laser diode. Then, ten teeth in each group were analyzed by SEM as morphological changes. The other ten teeth were filled and stained with Rhodamine B to evaluate the percentage of apical leakage. The results showed significant difference between G1 and G2 (p <0.001 - chi-square), checking greater presence of debris in G1 (control) and higher incidence of open dentinal tubules in G2 (PDT). Erosions and cracks were observed in both groups, with no statistically significant difference (p> 0.001). The percentage of apical leakage was significantly higher in G2 than in G1 (p <0.001 - t student). It was concluded that the use of the diode laser caused a reduction of smear layer and opening the dentinal tubules and does not influence the occurrence of erosion, cracks and carbonization. The laser increased the permeability of the apical dentine.