5. Endodontic Access Considerations Based on Root Canal Morphology

The odontoblast cells within dental pulp create the roots of teeth through a process of dentinogenesis during tooth development. Dental pulp initially occupies the root canal space within each root of a tooth. The root canal space containing dental pulp reduces in volume throughout life, because of dentinogenesis, which is the continual calcification and mineralization process of odontoblasts. As a patient gets older their root canals become more calcified and narrower, in old age the root canals of teeth can be completely calcified with no apparent dental pulp remaining. These continuing mineralization processes within the root canals of teeth give rise to alterations in root canal morphology which can present challenges for the ideal position of the endodontic access. The goal of the access is to locate and provide the direct access of files and instruments into the root canals of the tooth. The position and design of the access is determined by the size of the pulp chamber, the age of the tooth, previous restorative efforts, the long axis of the tooth, and root curvature. The location and design of the access cavity is dictated by the pulp chamber morphology of the tooth being treated. Achieving adequate access to the root canal is the key to accomplishing endodontic success. In order to remove the dental pulp the location of the coronal pulp chamber and the pulp within the roots must be visualized. To help visualize the location of the dental pulp, there are laws to be used to help position the access and find the orifices to root canals:Root canal centrality, Root canal concentricity, Dentin color change, Symmetry 1 and 2, and Orifice location 1 and 2. If the access is not adequate for endodontic treatment, it could compromise the cleaning, shaping and obturation of the root canals which could increase the risk of treatment failure.