Endodontic irrigation is crucial in dentistry as it focuses on cleaning and disinfecting the root canal system. For initiation of pain, primary etiological factor is microorganisms, predominantly bacteria. The persistence of microorganisms inside root canal is most common reason for failure of endodontic therapy and post-operative pain. Effective irrigation removes debris and bacteria, aiding in successful root canal treatments and preventing complications such as infection or reinfections. For eradication of root canal microorganisms, irrigation is the most important step in root canal treatment. Understanding irrigation techniques and solutions enhances overall quality of endodontic procedures, contributing to improved patient outcomes. ¹

Various root canal irrigation solutions are used for root canal irrigation. Sodium hypochlorite is the most commonly used irrigant solution because it has highest antimicrobial activity, ability to dissolve organic substances present in root canal, and is affordable. Even though it has high antibacterial activity, there are some limitations and disadvantages with such as high surface tension, which inhibits penetration of irrigants into the lateral canal and isthmus, etc. Use of sodium hypochlorite at high concentrations for a longer period of time can lead to changes in dentine collagen. To overcome the limitations of sodium hypochlorite, a newer irrigants with the higher antimicrobial activity will be sought. Many nanoparticles have been introduced for the disinfection of root canals as an antimicrobial agent.^2,3

Nanotechnology is a science that deals with the development of new surface properties and the restructuring of materials on a nano-meter scale of less than 100nm. Nanotechnology has been used in a wide range of endodontic applications. Chitosan, a deacetylated derivative of chitin, has been widely used in the medical field. It occurs in various forms, like powder, capsules, films, scaffolds, hydrogels, and beads. Chitosan nanoparticles have antibacterial, antiviral, and antifungal effects. Chitosan nanoparticles have the properties of biocompatibility, biodegradability, bioadhesion, chelating activity, and low toxicity to human cells. Chitosan nanoparticles can be used for root canal irrigation, to eliminate biofilm from root canals, and for tissue regeneration using membrane barriers in periapical surgery.^4,5.

Hence, this study aims to evaluate the postoperative pain and antibacterial effectiveness of 0.2% nano-chitosan and 2% sodium hypochlorite irrigating solutions in routine endodontic procedures among young adults.