A Comparison of Er : YAG Laser with Photon-Initiated Photoacoustic Streaming, Nd :YAG Laser,and ConventionalIrrigationon the Eradication of Root Dentinal Tubule Infection by Enterococcusfaecalis Biofilms : A Scanning Electron Microscopy Study

This study evaluated the antimicrobial efficacy of Er:YAG laser activation with photon-initiated photoacoustic streaming (PIPS),Nd:YAG laser disinfection, and conventional irrigation onEnterococcus faecalisbiofilms using scanning electron microscopy (SEM).Biofilms were grown on 110 root halves and divided into the following: Groups 1 and 2 (saline and 1% NaOCl with apical position ofPIPS, resp.), Groups 3 and 4 (saline and 1% NaOCl with coronal position of PIPS, resp.), Groups 5 and 6 (Nd:YAG laser after salineand 1% NaOCl irrigation, resp.) and Groups 7, 8, and 9 (conventional irrigation with 1% NaOCl, 6% NaOCl, and saline, resp.). SEMimages of the apical, middle, and coronal levels were examined using a scoring system. Score differences between Groups 1 and2 were insignificant at all levels in the remaining biofilm. Group 4 had significantly greater bacterial elimination than Group 3 atall levels. Differences in Nd:YAG laser irradiation between Groups 5 and 6 were insignificant. Groups 7 and 8 were insignificantlydifferent, except at the middle level. Saline group had a higher percentage of biofilms than the others. In this study, PIPS activationwith NaOCl eliminates moreE. faecalisbiofilms in all root canals regardless of the position of the fiber tip