"2022 Expert Consensus: Regenerative Endodontic Therapy"
I. Introduction
Regenerative endodontic therapy (RET) is an emerging treatment modality in the field of endodontics. The 2022 expert consensus aims to provide updated and comprehensive guidelines regarding RET based on the latest scientific evidence and clinical experience.
II. Indications for RET
Pulp necrosis in young permanent teeth: Young permanent teeth with pulp necrosis due to trauma, caries, or other reasons are the main candidates. The presence of an open apex or a root with incomplete development provides a more favorable environment for regenerative procedures. For example, a 12 - year - old patient with a maxillary central incisor that has pulp necrosis after a sports - related injury and an open apex is a typical case suitable for RET.
Selected cases of mature teeth: In some cases of mature teeth with periapical lesions and potential for pulp - dentin complex regeneration, RET may also be considered. However, the success rate and predictability in mature teeth are generally lower than in young permanent teeth.
III. Treatment Principles and Goals
The fundamental principle of RET is to promote the regeneration of the pulp - dentin complex. This involves creating a suitable biological environment to stimulate the proliferation and differentiation of dental pulp stem cells and other progenitor cells.
The main goals are to eliminate infection, induce new tissue formation (including pulp - like tissue and dentin - like tissue), and restore the normal physiological function and vitality of the tooth as much as possible.
IV. Clinical Procedures
A. Diagnosis and Treatment Planning
Comprehensive diagnosis: A thorough dental examination, including radiographic assessment (such as periapical radiographs and cone - beam computed tomography), pulp vitality testing, and evaluation of the root development stage, is essential. The extent of periapical lesions and the condition of the root canal system need to be accurately determined.
Treatment planning: Based on the diagnosis, a customized treatment plan is developed. Considerations include the choice of disinfection methods, the type of biomaterials to be used, and the expected follow - up schedule.
B. Root Canal Disinfection
Initial debridement: Thorough mechanical debridement of the root canal using endodontic instruments is the first step. This helps to remove necrotic pulp tissue and most of the bacteria.
Chemical disinfection: Various disinfectants can be used. Commonly, a combination of sodium hypochlorite and other irrigants (such as ethylenediaminetetraacetic acid, EDTA) is applied. The use of antibiotics - based intracanal medications is also a subject of research and clinical trials. However, the choice and concentration of disinfectants need to be carefully considered to avoid potential cytotoxicity and interference with the subsequent regeneration process.
C. Induction of Regeneration
Biomaterials: The use of appropriate biomaterials is a crucial aspect of RET. These biomaterials can act as scaffolds to support cell growth and differentiation. For example, platelet - rich plasma (PRP), platelet - rich fibrin (PRF), and some bioactive ceramics have been investigated for their potential to enhance the regenerative process. The biomaterials are carefully placed into the root canal to fill the space and provide a conducive environment for cell migration and tissue formation.
Growth factors: Growth factors such as transforming growth factor - beta (TGF - β), bone morphogenetic proteins (BMPs), and vascular endothelial growth factor (VEGF) are involved in the regulation of tissue regeneration. Some studies have explored the exogenous application of these growth factors to boost the regenerative potential of the treatment.
D. Sealing of the Root Canal
After the placement of biomaterials and any other necessary substances, the root canal is sealed. The choice of sealing materials is also important. Biocompatible and sealable materials are preferred to prevent bacterial leakage and provide a stable internal environment for the regeneration process. Commonly used materials include mineral trioxide aggregate (MTA) and some resin - based sealers.
V. Follow - up and Evaluation
Short - term follow - up: In the short - term (usually within a few weeks to a few months), the focus is on monitoring the patient's symptoms, such as pain, swelling, and any signs of infection. Radiographic evaluation may also be carried out to observe any changes in the periapical area and the root canal space.
Long - term follow - up: Long - term follow - up (ranging from months to years) is crucial to assess the success of RET. Criteria for success include the absence of symptoms, resolution of periapical lesions, and evidence of new tissue formation in the root canal (such as the presence of pulp - like or dentin - like tissue). The stability of the tooth and its normal physiological function (such as normal response to pulp vitality testing) are also important evaluation factors.
VI. Complications and Management
Infection recurrence: If infection recurs, it may require re - evaluation of the root canal disinfection protocol and possible re - treatment. This may involve additional mechanical debridement, more aggressive chemical disinfection, or even a change in the treatment approach.
Insufficient tissue regeneration: In cases where the expected tissue regeneration does not occur, the reasons need to be investigated. It could be due to improper biomaterial selection, suboptimal growth factor application, or other factors. Management strategies may include secondary interventions such as additional stimulation of the regenerative process through different biomaterials or growth factor combinations.
VII. Future Directions
Research is still needed to optimize the biomaterials and treatment protocols for RET. The development of more effective and biocompatible scaffolds, as well as a better understanding of the role of growth factors and cell signaling pathways, will enhance the predictability and success rate of RET.
Standardization of clinical evaluation methods and long - term follow - up studies across different centers are also essential to build a more reliable evidence - base for this innovative treatment modality.