Clinical outcomes of regenerative endodontic treatment with injectable platelet-rich fibrin in mature necrotic teeth in a retrospective cohort study.

Conventional root canal treatment eliminates infection in necrotic permanent teeth but does not restore the dentin-pulp complex. The clinical predictability of regenerative endodontic treatment in mature teeth remains uncertain. This study evaluated the clinical and radiographic outcomes of an injectable platelet-rich fibrin (i-PRF)-supported regenerative protocol in mature necrotic teeth. This retrospective two-center cohort study included mature permanent teeth presenting with pulp necrosis, closed apices, and periapical lesions with a periapical index (PAI) score ≥ 3 treated between 2022 and 2025 using a standardized i-PRF-supported regenerative endodontic treatment protocol. Periapical healing was assessed using PAI scores, with cone-beam computed tomography (CBCT) images serving as supplementary three-dimensional illustrations. Postoperative pain was recorded using the Visual Analog Scale (VAS). Statistical analysis was performed using the Wilcoxon signed-rank test, Friedman test with Dunn post hoc analysis, logistic regression, and receiver operating characteristic (ROC) curve analysis. A total of 27 teeth were included, with a mean follow-up of 22.5 months. Clinical success was achieved in 24 teeth (88.9%). Mean PAI scores decreased significantly from 4.3 ± 0.78 preoperatively to 1.07 ± 1.57 at follow-up (p < 0.001). CBCT images showed radiographic evidence of three-dimensional periapical healing. Postoperative pain was minimal, with median scores reaching zero within 72 h and no need for analgesic medication. No significant predictors of treatment failure were identified. Within the limitations of this two-center retrospective study, i-PRF-supported regenerative endodontic treatment in mature necrotic teeth demonstrated favorable clinical outcomes, periapical healing, and low postoperative pain, suggesting its potential as a biologically based management approach.