Antimicrobial substantivity of root canal irrigants and medicaments: a review

Disinfection of the root canal system is one of the primary aims of root canal treatment. This can be achieved through the use of various antimicrobial agents in the form of irrigants and medicaments. These agents are only used for relatively short periods of time ranging from minutes (for irrigants) up to days or several weeks (for medicaments) and therefore their long-term antimicrobial effects rely on whether or not the particular agent has any properties of substantivity. If irrigants and medicaments had effective long-term residual antimicrobial activity that could prevent re-infection of the root canal system, then the long-term outcomes of endodontic treatment might be improved. Only a small number of studies have investigated the short-term substantivity of commonly used antimicrobial agents and the results show substantivity of chlorhexidine lasts for up to 12 weeks and tetracycline for up to 4 weeks. However, it is not known whether the substantivity of these agents will last for longer periods of time as this has not been investigated.