The search for new ways of treatment has led to numerous findings and significant results in the field of regenerative endodontics in recent decades. The main goal of regenerative endodontics is to preserve the tooth in the oral cavity by creating functional new tissue that will replace the role of dental pulp. In this way regenerative endodontics aims to prevent the loss of function of the tooth itself and reduce possible fractures, which often happens with endodontically treated teeth. Teeth can be treated by regenerative procedures at any stage of their development. Immature permanent teeth with unfinished root development are treated by methods of revascularization, causing bleeding from the periapex to form the coagulum that serves as the basis for the regeneration of the pulp tissue. On the other hand, mature teeth with full root development and a closed apex are treated by tissue engineering methods. Stem cells are the subject of research in all branches of medicine, as well as dentistry. Many oral tissues have turned out to be a source of stem cells from which new regenerated tissues can be created by different procedures. New research includes growth factors and specifically designed scaffolds to improve stem cell activity. The ideal outcome of the regenerative process is an asymptomatic tooth that no longer needs re-surgery.