Clinical procedures for revitalization: current knowledge and considerations

Revitalization or regenerative treatment approaches in teeth with incomplete root formation and pulp necrosis have become part of the therapeutic endodontic spectrum and should be considered as an alternative to conventional apexification. Ideally, regenerative endodontic procedures allow not only for a resolution of pain, inflammation and periapical lesions, but also for the formation of an immunocompetent tissue inside the root canal which can reconstitute the original biological structure and function of dental pulp and thus lead to an increase in root length, and thickness and strength of previously thin, fracture-prone dentine walls. Common features of regenerative procedures performed in immature teeth with pulp necrosis include (i) minimal or no instrumentation of the dentinal walls, (ii) disinfection with irrigants, (iii) application of an intracanal medicament, (iv) provocation of bleeding into the canal and creation of a blood clot, (v) capping with calcium silicate, and (vi) coronal seal. Although case reports and case series provide promising results, the protocol for regenerative endodontic treatment is not fully established; questions remain regarding the terminology, patient selection and informed consent as well as procedural details, especially on the choice of irrigants, intracanal medicaments and materials for cavity sealing. Animal studies document repair rather than regeneration, which opens the discussion on prognosis and outcome, especially the biological versus the patient-based outcome. This review will provide an overview of the current state of regenerative endodontic therapies, discuss open questions and provide recommendations based on the recent literature.