Regenerative endodontic procedures (REPs) are valuable treatment options for immature permanent teeth with pulpal necrosis. A large number of case reports and basic research articles, but only a few systematic studies, have been published on this subject. Clarifying whether a research finding is useful for the dental clinic or still basic research is not easy for practitioners. A step-by-step treatment protocol reflecting the current state of science and technology and excluding experimental methods is presented in this chapter. References are also included that provide assessment criteria for evaluating the probability of success of REPs. Evaluations of criteria for successful clinical treatment and further treatment options have increasingly shown the applicability of REPs.