Outcome of regenerative endodontic procedures in delayed replanted immature permanent teeth with apical periodontitis: A retrospective study

Abstract Background Regenerative endodontic procedures (REPs) is effective for treating young permanent teeth with pulp necrosis. However, its efficacy on delayed replanted avulsed teeth is unclear. Aim This retrospective study aimed to assess the efficacy of REPs in treating delayed replanted immature permanent teeth with apical periodontitis. Design Avulsed teeth receiving REPs were systematically screened based on predetermined criteria. This study assessed the REP outcomes, postoperative periodontal healing, and overall treatment efficacy. Samples were grouped by REP outcomes and root development stage, with Fisher's exact tests used to compare outcomes among different groups. Results Among the included 17 teeth, 47.1% exhibited successful REPs and periodontal healing. Another 47.1%, due to replacement resorption or REP failure, were categorized as tooth survival. Healing of periapical lesions was observed in 88.2% of the cases, but only 41.2% demonstrated continued root development. Although differences were not significant ( p = 0.05), teeth with continued root development had a higher rate of functional healing (85.7%) compared to those without (30%). Conclusion Within the limitations of this study, REPs presented reliable outcomes for treating delayed replanted immature permanent teeth with apical periodontitis mainly in periapical lesion healing. Teeth with continued root development after REPs exhibited a higher rate of functional healing. Further investigation is required to explore potential synergies between REP outcomes and periodontal healing.