Disinfection Efficacy of Laser Activation on Different Forms and Concentrations of Sodium Hypochlorite Root Canal Irrigant against IEnterococcus faecalis/I in Primary Teeth

Photoactivated disinfection with sodium hypochlorite (NaOCl) has improved primary root canal treatment outcomes. This in vitro study aims to assess and compare the disinfecting efficacy of 2.5% sodium hypochlorite solution and 5.25% sodium hypochlorite gel, without laser activation and accompanied by laser activation, on Enterococcus faecalis-contaminated primary teeth root canals. After one month of incubating extracted teeth specimens with E. faecalis, 36 specimens were randomly divided into two groups: Group A (conventional method without laser-activated irrigation) and Group B (with laser-activated irrigation). Each group was further divided into three subgroups, with six samples in each subgroup. Subgroup 1 received irrigation with normal saline, Subgroup 2 with 2.5% sodium hypochlorite solution, and Subgroup 3 with 5.25% sodium hypochlorite gel. Diode laser activation at 810 nm was used in Group B. Bacterial colony counts were measured before and after the intervention. Student’s t-test and one-way analysis of variance (ANOVA) with Tukey’s post hoc test were used for statistical analysis. The significance level was set at p < 0.05. Microbial analysis revealed no bacterial growth in samples irrigated with 5.25% sodium hypochlorite gel activated with the laser. Activation with the laser significantly (p = 0.02) improved the disinfection ability of the irrigant compared to the non-activation group. The disinfection ability of sodium hypochlorite gel was better than that of saline (p = 0.02); however, it was comparable to that of sodium hypochlorite solution (p = 0.67). Conclusion: Root canal irrigation with 5.25% sodium hypochlorite gel activated with an 810 nm diode laser resulted in complete eradication of Enterococcus faecalis, indicating its effectiveness as an endodontic disinfection treatment modality.