Root canal treatment may be carried out as an alternative to dental extraction on a tooth in which the nerve has been injured or has died. Root canal treatment is carried out because the offending canal is infected or the pulp severely inflamed. The aim of root canal treatment is to eliminate bacteria from, and prevent their further entry to the root canal system. The technique involves cleaning and removal of any remaining bacteria and nerve canal contents. Elimination of any remaining infection improves the chance of success, and irrigation of the canal with certain types of solutions during the procedure can be helpful in achieving this. A range of antiseptic and antibacterial irrigating solutions are available. Sodium hypochlorite (NaOCl) in a variety of strengths has been used by dentists for many years, but concerns have been raised about its toxicity and the occasional report of pain when higher concentrations are used. Chlorhexidine, an antimicrobial, has also been used in a variety of concentrations as either a solution or gel. Combinations of antibiotic and a detergent (MTAD) have been recently developed and are being used increasingly.
This review evaluated 11 studies which included 851 participants with 879 front and back teeth which had undergone root canal treatment. Sodium hypochlorite in a range of strengths was the most commonly used irrigating solution, followed by chlorhexidine as a solution or a gel. The amount of pain experienced immediately after treatment and between appointments did not appear to differ either between some of the irrigants or between the different strengths of individual irrigants. Limited data suggested that higher strength concentrations of sodium hypochlorite solution and a final rinse with chlorhexidine may be more effective than other irrigants at destroying bacteria.