Favorable Eruption Despite External Replacement Root Resorption in Delayed Replantation of Avulsed Teeth Treated With Regenerative Endodontics—An Observational Study

Abstract

Aim: To assess the eruption patterns and progression of external replacement root resorption of eight teeth that were avulsed and had delayed replantation treated by regenerative endodontic treatment (RET). Methodology: In total, 102 traumatised anterior teeth were treated with regenerative endodontic treatment (RET) between December 2016 and December 2023. Of the 17 teeth that had avulsed, 8 that had been replanted after at least 30 min subsequently developed external inflammatory root resorption (EIRR). Patient ages ranged between 8 and 11 years. The RET followed the IADT 2020 guidelines and the protocol of the American Association of Endodontists guidelines. Under rubber dam, the teeth were accessed, the canals disinfected with 3% sodium hypochlorite, and dressed with a triple antibiotic paste consisting of metronidazole, cefuroxime, and ciprofloxacin. At the second visit, the canal was filled with plasma-rich fibrin (PRF) after ensuring bleeding from the periapical tissues. A resorbable collagen tape was placed above the PRF and covered with Biodentine, followed by a permanent restoration. The patients were followed up for 18–72 months. Results: The eight avulsed teeth with delayed replantation diagnosed with pulp necrosis and EIRR were treated with RET, which arrested the EIRR. The teeth were subsequently diagnosed with external replacement root resorption (ERRR), which was generally progressive and classified as slow, moderate, or fast. The striking finding was that seven of the eight teeth did not develop infraposition, a showing favorable eruption patterns despite progressive and advancing ERRR. The remaining tooth developed only slight infraposition despite progressive ERRR. None of the teeth were lost, and in all cases, the alveolar ridge was preserved. Conclusion: RET appeared to prevent the development of infraposition expected in teeth with delayed replantation following avulsion, due to its promotion of favorable eruption. RET may offer the most effective endodontic solution after avulsion and reimplantation, as it arrests EIRR and can preserve the alveolar ridge height and gingival line by preventing the occurrence of ankylosis, thereby eliminating the need for decoronation.