Laser And Dnase-I For Biofilm Removal In Lateral Canal

To investigate the efficacy of a novel combination of Nd:YAP laser and DNase-I in removing dual-species biofilms from dentine surfaces, using a 3D-printed lateral canal model. A 3D-printed root canal model with a lateral canal was fabricated to simulate the anatomical complexity. A computational fluid dynamics (CFD) model assessed the impact of needle-insertion depth on irrigant flow. Dual-species biofilms (Enterococcus faecalis and Fusobacterium nucleatum) were cultured on dentin discs for one week. Infected samples were assigned to four irrigation protocols: Group A (1% NaOCl), Group B (DNase-I + 1% NaOCl), Group C (1% NaOCl + laser), and Group D (DNase-I + 1% NaOCl + laser). Bacterial adhesion and dentine structure were observed using scanning electron microscopy (SEM). The number of viable bacteria was quantified by confocal laser scanning microscopy (CLSM). SEM and CLSM confirmed the successful formation of dual-species biofilm. All experimental groups showed a significant reduction in viable bacteria compared to the control (p < 0.05), with Group D achieved the highest clearance rates (98.02% at WL-3 mm and 95.70% at WL-6 mm). As needle insertion depth decreased, the irrigant velocity in the lateral canal declined, leaving more viable bacteria attached. Needle-insertion depth is critical for effective biofilm removal in lateral canals. The Nd:YAP laser combined with DNase-I enhances irrigant delivery and biofilm dispersion, presenting a promising strategy for improving lateral canal disinfection in vitro.