Eradication of endodontic infection by instrumentation and irrigation solutions

Debridement of the root canal by instrumentation and irrigation is considered the most important single factor in the prevention and treatment of endodontic diseases. In clinical practice, instrumentation of the root canal(s) within the affected tooth is usually the most time consuming and technically demanding element of the treatment. The technical success of the treatment, as judged by the post-operative radiograph after the root filling, is based on optimized root canal instrumentation. Mounting evidence from epidemiological research is also indicating that the combination of high-quality coronal restoration and technically satisfactory root canal treatment is associated with the greatest long-term prognosis. Therefore, it is not surprising that for several decades of endodontic research, a substantial number of articles on instruments and instrumentation have been published in the scientific literature. Although interest in the effects of instrumentation on intracanal infection is not new, it is obvious that during the last few years a renewed focus of interest has appeared on the relationship between instrumentation and infection control in the root canal. The ongoing discussion in international endodontics about one-appointment therapy in the treatment of apical periodontitis has naturally further motivated the newly emerged research activities. The goal of this review is to gather the relevant and most recent literature and provide an updated analysis of the effect of preparation (instrumentation and irrigation) on the microbial infection in the necrotic root canal.