In vivo evaluation of root canal disinfection using a combination of ultrasonic activation and diode laser therapy

J Conserv Dent Endod. 2025 Jun;28(6):510-514. doi: 10.4103/JCDE.JCDE_158_25. Epub 2025 Jun 2.

Abstract

Aim: In vivo evaluation of root canal disinfection using a combination of ultrasonic activation and diode laser therapy.

Objective: The primary aim of this study was to evaluate the effectiveness of ultrasonic activation of sodium hypochlorite and diode laser irradiation in enhancing root canal disinfection by reducing bacterial load.

Materials and methods: Thirty patients aged 20-60 years with necrotic lower premolars and periapical infections were selected. After access opening, initial microbial samples (S1) were collected. The canals were then instrumented using ProTaper Next rotary files and irrigated with 2.5% sodium hypochlorite, which was activated ultrasonically using EndoX for 1 min. The second microbial sample (S2) was collected. Subsequently, 980 nm diode laser irradiation was applied in a pulsed mode, and the final microbial sample (S3) was obtained. All the samples were cultured in Brain Heart Infusion Agar (BHI) agar, and colony-forming units (CFU/ml) were determined. Statistical analysis was performed using the SPSS software with a significance threshold of P ≤ 0.05.

Results: The mean CFU/ml count significantly reduced from S1 (22.93) to S2 (6.03) after ultrasonic activation and further decreased to S3 (1.04) following diode laser application. The reduction was statistically significant (P < 0.001).

Conclusion: The combination of ultrasonic activation of sodium hypochlorite and diode laser irradiation significantly enhances root canal disinfection. Ultrasonic activation improves irrigant penetration, while diode laser provides deeper antimicrobial action.

Keywords: Diode laser; microbial reduction; root canal disinfection; sodium hypochlorite; ultrasonic activation.