Effects of Diode Laser, Gaseous Ozone, and Medical Dressings onEnterococcus faecalisBiofilms in the Root Canal Ex Vivo

Abstract

The objective was to compare the antibacterial effects of adjunctive disinfection using diode laser and gaseous ozone compared to the medical dressings calcium hydroxide (Ca(OH)2) and chlorhexidine gel (CHX-Gel) onEnterococcus faecalisbiofilms in human root canals ex vivo. Root canals of 180 human extracted teeth were infected byE. faecalisand divided into 3 main groups (G): G1, control; G2, instrumentation and irrigation using 0.9% NaCl; G3, instrumentation and irrigation using 1% NaOCl. In each main group, the following treatments were applied: gaseous ozone, diode laser, and medical dressings of Ca(OH)2or CHX-Gel for 7 days (n=15). Reduction of colony forming units (CFUs) inside the root canal of planktons and frequencies of adherent bacteria after treatment were calculated. Bacterial reduction was significantly affected by the irrigation protocol (p<0.0005) and the disinfection method (p<0.0005), and a significant interaction between both factors could be observed (p<0.0005; ANOVA). In G3 (instrumentation using 1% NaOCl), no significant effect of disinfection methods could be demonstrated on planktonic bacteria (p=0.062; ANOVA) and frequencies of adherent bacteria (p>0.05; chi-square test). Instrumentation and irrigation using NaOCl combined with ozone or laser application resulted in comparable bacterial reduction onE. faecalisto the application of medical dressings.