Evaluation of the bactericidal effect and permeability changes on root dentin after er, cr:YSGG laser and diode laser irradiation

Primary purpose of the endodontic treatments is to remove the microorganisms and their products. The complete elimination of the microorganisms from the root canals is not simple due to the root canal anatomy and the smear layer composed during the mechanical preparation. Latest researchs shows that the laser technology is a useful method for root canal disinfections. The aim of our study is evaluate of the antimicrobial efficacy on Enteroccus faecalis and permeability changes on root dentin after Er,Cr:YSGG laser and diode laser irradiation. 90 single rooted, single canalled human incisive teeth were used in the study. Root canals were contaminated with E.faecalis bacterial suspension. Samples were randomly divided into expermental and control groups: Group 1: 5% NaOCl, Group 2: Er:Cr:YSGG laser (1.25W, 20Hz, 24% water, 34% air, 40s irradiation), Group 3: NaOCl 5% activated with Er:Cr:YSGG laser (1.25W, 20Hz, water -air off, 40s irradiation) Group 4: Er:Cr:YSGG laser and diode laser (Er:Cr:YSGG: 1.25W, 20Hz, 24% water, 34% air; Diode laser: 4.5W power CP1 mod aeverage power 1.5W, total 80s irradiation), positive and negative control groups. The root canals were filled with methylene blue dye for the analysis of the dentin permeability following the microbiological sampling. The samples were divided horizontally into 3 sections. The sections are imaged in stereomicroscope and measured the ratio of the colored area to the whole area. In conclusion of the study showed that all the methods used in the experimental groups are effective in E.faecalis disinfection. There was no significant difference between irradiation with Er,Cr:YSGG laser or Er,Cr:YSGG and diode laser. According to dentin permeability and antimicrobial analysis, NaOCl 5% activated with Er,Cr:YSGG laser can be an ideal method for root canal disinfection.