Antibacterial Efficacy and Outcomes of Root Canal Irrigation Methods

After supragingival scaling and removal of caries or defective restorations, the tooth will be isolated and disinfected with 3% H202 and 2.5% NaOCl. Access preparation will be done using a sterile high-speed bur under sterile saline irrigation, followed by re-disinfection. NaOCl will be neutralized with 5% sodium thiosulphate, and sterility will be confirmed via paper point sampling. Only teeth with negative sterility samples will proceed. Sample S1 will be collected after saline irrigation and mild instrumentation with a sterile K-file #15, using an apex locator. Paper points will absorb canal fluid and be frozen in Tris-EDTA buffer at -20°C. Complete chemomechanical preparation will follow, with irrigation after each instrument change. Cervical and mid-thirds will be enlarged with Gates-Glidden burs and the apical third with NiTi RaCe files (40/04). Sample S2 will be taken after preparation. Group A will receive final irrigation with 2.5% NaOCl before collection of sample S3.

Activation of 2.5% sodium hypochlorite solution inside the root canal system using Passive Ultrasonic Irrigation (PUI) after chemomechanical preparation. Group B, sample (S3).

Mechanical activation of 2.5% sodium hypochlorite solution using the XP-Endo Finisher instrument following chemomechanical preparation.Group C, sample (S3).