Fluid Dynamics of Irrigation within the Root Canal System

The subject of endodontic fluid dynamics is wrought with myths, misunderstood observations, prejudices, biases, or often a simple lack of understanding. Accordingly, it is necessary to identify and explain these misconceptions, via evidence-based studies, that have unwittingly been embedded into the subject. These include (i) apical vapor lock effect, (ii) hydrolysis of organic components of the soft and hard pulp tissues and canal wall biofilms, (iii) technique misunderstandings, and (iv) patency safety issues. Following these demystifications, evidence-based studies should be used to identify strategies for attaining safe and effective intra- and extracanal irrigant fluid dynamics. The subject of this chapter is fluid dynamics of irrigation within the root canal system. For effective debridement, there must be an exchange of irrigants throughout the root canal system including canal fins, cul-de-sacs, and isthmus areas.