Book excerpt: This book reviews the available information on bacterial disinfection in endodontics, with emphasis on the chemical treatment of root canals based on current understanding of the process of irrigation. It describes recent advances in knowledge of the chemistry associated with irrigants and delivery systems, which is of vital importance given that chemical intervention is now considered one of the most important measures in eliminating planktonic microbes and biofilms from the infected tooth. Recommendations are made regarding concentrations, exposure times and optimal sequences. Possible complications related to the use of the different solutions are highlighted, with guidance on response. In addition, clinical protocols are suggested on the basis of both clinical experience and the results of past and ongoing research. Throughout, a practical, clinically oriented approach is adopted that will assist the practitioner in ensuring successful endodontic treatment.