Atividade antibacteriana da terapia fotodinâmica na desinfecção dos canais radiculares associada a diferentes protocolos de irrigação

Abstract

The objective of this study was to evaluate, in vitro, the antibacterial activity of photodynamic therapy associated with different irrigation protocols in the control of Enterococcus faecalis (E. faecalis) on the root canal system. It was an experimental trial in which a total of 80 unirradicular human premolars were prepared and contaminated with 0.1 ml of E. faecalis (3 x 108 cells / ml) for a four days period. The teeth were randomly divided into six groups: Group C + (conventional needle irrigation); Group C - (negative control); PDT group (photodynamic therapy); NaOCl + PDT group (2.5% sodium hypochlorite + photodynamic therapy); IUP + PDT group (passive ultrasonic irrigation + photodynamic therapy); XP Endo Group + PDT (XP Endo Finisher + photodynamic therapy). The light source used was a low- intensity diode laser with wavelength of 660 nm, power of 100 mW and energy of 9 J, for 90 seconds of irradiation. The dye used was 0.005% methylene blue. The contents of the root canal were collected with sterile absorbent paper tips in two moments: before the decontamination protocols and 24 hours after the protocols. The number of colony forming units of E. faecalis (CFU) was determined for each root canal. The ANOVA and TUKEY tests were used and the level of significance was set at 5% (p <0.05). The percentage of inhibition ranged from 10.72 (C-) to 100% (XP Endo + TFD), and the values of CFU / mL were different among all the protocols tested (p <0.05). In addition, the different protocols tested significantly influenced bacterial inhibition (p <0.05). The protocol that provided the highest percentage of bacterial inhibition was XP Endo + PDT (100.0%), followed by NaOCl + PDT (65.85%). After this study, it was concluded that PDT associated with different protocols of final irrigation was more effective in inhibiting E. faecalis than in its isolated use, with XP Endo Finisher being the best irrigation protocol in the fight against this microorganism.