Different-Wavelength Lasers In Root Canal Disinfection

To compare the antibacterial efficacy of ultrasonic activation (UA), Er,Cr:YSGG laser, Er:YAG laser, and thulium fiber laser (TFL) in root canal treatment. Thirty-two extracted single-rooted teeth were instrumented and randomly assigned to four groups (n=8 each): UA, Er,Cr:YSGG, Er:YAG, or TFL. Specimens were inoculated for 48 hours with a polymicrobial suspension containing Staphylococcus aureus, Streptococcus mutans, Prevotella intermedia, Enterococcus faecalis, and Porphyromonas gingivalis. Bacterial elimination was quantified using colony-forming unit counts before and after treatment, supplemented by scanning electron microscopy (SEM) evaluation of residual biofilm. Statistical analysis was performed using SPSS 22.0. All groups demonstrated >90% bacterial reduction (P<0.05). While no significant differences were observed among the three laser groups (P>0.05), all laser modalities significantly outperformed UA (P<0.05). SEM analysis revealed substantially less residual biofilm in laser-treated canals. Laser-activated irrigation (particularly Er,Cr:YSGG, Er:YAG, and TFL) significantly enhances root canal disinfection efficacy, potentially improving clinical outcomes in endodontic therapy.