Comparison of the antimicrobial effects of Er:YAG (PIPS) and Nd:YAG lasers in the root canal on enterococcus faecalis and candida albicans

This study aimed to evaluate the antimicrobial efficiency of Nd:YAG and Er:YAG (PIPS) lasers on Enterococcus faecalis and Candida albicans grown in root canals of extracted teeth. One hundred and forty single-rooted human mandibular premolars were selected for the study. After preparation and sterilization, the samples were divided into 2 groups. Root canals in Group 1 were infected with E. faecalis while others in Group 2 were infected with C. albicans. Each sample (except negative control groups) was inoculated with 105 cfu/ml and a volume of 10 µl of microorganisms. After 4 weeks of incubation, the teeth were randomly divided into 10 subgroups; 1A: Nd:YAG laser (n=20), 1B: Er:YAG (PIPS) laser + NaOCl (n=20), 1C: 5% NaOCl (n=20) , 1D: positive control (n=5), 1E: negative control (n=5), 2A: Nd:YAG laser (n=20) , 2B: Er:YAG (PIPS) laser + NaOCl (n=20), 2C: 5% NaOCl (n=20) , 2D: positive control (n=5) , 2E: negative control (n=5). After the disinfection procedure, the culture of each sample was estimated immediately to determine the cfu/ml values. The data were analyzed with the Kruskal Wallis and Dunn tests. Er:YAG (PIPS) laser + NaOCl , NaOCl and Nd:YAG laser groups presented a significant reduction in the number of viable microorganisms obtained from the root canal following the disinfection procedure (p<0.05). There was no significant difference in terms of microorganism elimination between irrigation with NaOCl alone and activation of the irrigation solution with the Er:YAG (PIPS) laser. NaOCl was already a very strong disinfectant.