Optimising single-visit disinfection with supplementary approaches: a quest for predictability.

Reduction of the bacterial populations to levels compatible with periradicular tissue healing is the primary microbiological goal of the endodontic treatment of teeth with apical periodontitis. New systems and substances have been proposed to improve root canal disinfection either by replacing conventional chemomechanical procedures or by supplementing their effects. This review focuses on supplementary approaches for optimised single-visit disinfection (OSD). The main OSD strategies reviewed include: final rinse with chlorhexidine, MTAD or iodine potassium iodide; sonic or ultrasonic activation of NaOCl; and photodynamic therapy. It is concluded that some OSD approaches may have the potential to improve disinfection in a single visit, but most of the results so far represent low-level evidence. There is no consistent clinical evidence showing that any of these OSD approaches can predictably reduce the bacterial bioburden in infected root canals to levels significantly below that achieved by chemomechanical procedures and to the point of eliminating the need for an antimicrobial inter-appointment medication. Therefore, while expediting disinfection is a goal that has been pursued, there is a need for the currently proposed protocols to be consistently evaluated for clinical effectiveness or new ones to be devised and tested before OSD is considered a predictable approach.