OBJECTIVES: Regenerative endodontic procedures (REPs), which have become a preferred biologically based approach for immature permanent teeth with pulp necrosis, aim to achieve periapical healing and continued root maturation. Therefore, this study aimed to comprehensively evaluate the clinical and radiographic outcomes of REPs and explore potential prognostic indicators associated with treatment outcomes in immature permanent teeth. MATERIALS AND METHODS: This study evaluated immature permanent teeth treated with REPs between 2018 and 2024, with a minimum follow-up of 12 months. Clinical and radiographic data were retrieved from standardised treatment/recall forms and periapical radiographs. Radiographic measurements (apical diameter, root length and radiographic root area RRA) were performed on ImageJ, and periapical healing was categorised as healed, healing or disease. Secondary outcomes comprised quantitative radiographic measures and tertiary outcomes comprised pulpal sensibility. Associations between clinical-radiographic variables and treatment outcomes were evaluated using binary logistic regression for primary outcomes and linear regression analyses for continuous radiographic parameters, with statistical significance set at p < 0.05. RESULTS: Twenty-one teeth were included (mean age: 16.9 years; 61.9% anterior). During the follow-up, 95.2% of the cases were classified as 'healed' or 'healing' and 4.8% as 'disease', according to the primary outcome criteria. Secondary outcomes were positive in 95.2% of the cases, whereas tertiary outcomes were positive in 28.6%. Quantitative analysis showed a mean increase in root length of 12.06 ± 8.1% and a mean increase in RRA of 45.91 ± 28.47%. The median percentage change in apical diameter was 59.10% (P25-P75 = 20.07-77.32), and the median percentage reduction in periapical radiolucency size was 85.36% (P25-P75 = 6.74-310.84). Increased age showed an association with higher odds of a diseased outcome (p = 0.010) and with reduced percentage changes in root length (p = 0.045) and RRA (p = 0.038). Anterior teeth demonstrated greater root length gains than posterior teeth (p = 0.045), while advanced root development stage and larger baseline apical diameter were associated with diminished root length changes (p ≤ 0.01). CONCLUSIONS: REPs yielded a high rate of periapical healing and consistent radiographic signs of continued root maturation at follow-up, while sensibility recovery remained limited. Age and baseline radiographic characteristics were associated with clinical and radiographic outcome measures. Accordingly, these variables may be considered as potential prognostic indicators during case selection, treatment planning and follow-up of REPs. CLINICAL RELEVANCE: REPs may support periapical healing and continued root maturation in immature permanent teeth with pulp necrosis; however, limited pulpal sensibility recovery suggests that these outcomes should not be equated with predictable restoration of pulp vitality. Age and baseline root morphology may help clinicians estimate regenerative potential, guide case selection and individualize follow-up, although these exploratory associations require cautious interpretation.
Kiraz et al. (Tue,) studied this question.