Continued Root Development Following iRoot BP Plus Apical Barrier Placement 3-4mm Short of Apex in Immature Permanent Teeth: A Retrospective Case Series Study

Abstract The apical barrier technique using bioceramic materials is established for treating immature permanent teeth with pulp necrosis. This study reports an unexpected observation: continued root development when iRoot BP Plus was inadvertently placed 3-4mm short of the radiographic apex. This retrospective case series analyzed four immature permanent teeth where iRoot BP Plus apical barrier was placed 3-4mm short of the apex due to technical factors, between October 2020 and December 2022, with follow-up periods of 22–48 months (mean: 32.5 months). All patients were male, aged 8–12 years. Affected teeth included mandibular second premolars and maxillary central incisor. Clinical diagnoses included acute pulpitis (n = 1) and apical periodontitis (n = 3). Treatment involved chemomechanical debridement, calcium hydroxide intracanal medication, followed by iRoot BP Plus placement which was positioned 3-4mm from the radiographic apex. Despite suboptimal material placement, all cases (100%) achieved periapical healing. Remarkably, three cases (75%) demonstrated continued root development with progressive apical closure beyond the bioceramic material, while one case showed periapical healing without significant root development. These unexpected findings suggest that placing iRoot BP Plus 3-4mm short of the apex may preserve the apical papilla and its stem cells (SCAPs), allowing continued physiological root development. This observation warrants prospective investigation as a potential intentional treatment modification.