One of the main functions of the dental pulp is formation of dentin. When the pulp undergoes pathologic changes before complete root development, normal root growth is disrupted. If the pulp is reversibly inflamed due to caries or exposure, the treatment of choice is to maintain pulp vitality by pulp capping or pulpotomy. The consequence of pulpal necrosis in immature teeth is the cessation of root development, making endodontic treatment with conventional techniques and materials difficult or impossible. Treatment options for these teeth include: apexification, regenerative endodontics or a new tooth. Apexification procedures that involve the production of an induced or artificial apical stop can allow for condensation of obturation materials. An ideal treatment for a necrotic immature tooth is the regeneration of pulp tissue into a canal and promotion of the normal root development. In this lecture we will discuss the pros and cons of pulp regeneration and the alternative treatments for teeth with pulp necrosis and open apexes.

Regardless of the fact that filling root canal space is essential for periapical healing, endodontic retreatment procedures might induce cracks during removal of pre-existing root canal filling materials. In addition, the method of root canal obturation during initial endodontic treatment might affect induction of cracks and tooth susceptibility to vertical root fractures following removal of filling materials and preparation of the root canal space. The teeth initially obturated by warm vertical compaction exhibit more cracks following retreatment compared to the teeth that received single-cone technique or cold lateral condensation as the initial obturation techniques.

Practitioners should always consider preparation and obturation techniques that apply lower pressure on the root canal wall such as single-cone technique using bioceramic sealers and the pure mineral trioxide aggregate (MTA) obturation which does not generate pressure inducing cracks. Besides this, MTA has many advantages over the use of gutta-percha and sealer especially in retreatment cases.
In the lecture those advantages of MTA obturation over gutta-percha and sealers in retreatment and an easy MTA obturation technique will be shown with many case reports.