Sodium hypochlorite is the most commonly used intracanal irrigant due to its excellent ability to dissolve organic tissue remnants within the root canal system and its broad-spectrum antimicrobial activity. It effectively eliminates bacteria, biofilms, and necrotic tissue, which are critical for successful endodontic treatment. Additionally, sodium hypochlorite helps in flushing out debris and prevents reinfection. Its superior tissue dissolution capacity distinguishes it from other irrigants like chlorhexidine or EDTA, which primarily have antimicrobial or chelating properties but lack significant tissue dissolving effects. These properties make sodium hypochlorite indispensable in root canal disinfection protocols.
Reference: Ingle's Endodontics, 7th Edition.