Segmental root development of immature necrotic permanent teeth following regenerative endodontic procedures: a case series

Regenerative endodontic procedures (REPs) are frequently utilized to treat immature permanent teeth with necrotic or inflamed pulps. In most instances, these treatments successfully result in the resolution of apical periodontitis and continued root maturation. However, after reviewing over 180 REP cases treated in the Endodontics Department of Stomatology Hospital at Zhejiang University School of Medicine over the past seven years, we identified an unusual root development pattern in ten cases, characterized by root tips detached from the root body. We conducted a comprehensive analysis of the patients' demographic information, dental histories, and therapeutic efficacy, and identified five potential etiological factors for this rare phenomenon, including external force, prolonged extensive periapical inflammation, iatrogenic factors, traumatic history of primary teeth, and excessive tooth mobility. In our study, we observed that therapeutic failure was more likely in patients with initially separated root tips, while those with initially normal teeth demonstrated significantly better prognoses. We hypothesize that the initial root condition may exert a considerable influence on treatment outcomes.