Adult tooth regeneration: can blood beat biomaterials? A COMMENTARY ON Awawdeh L, Almesleh B, Hammouri H, Al-Qudah A The outcome of pulp revascularization of necrotic mature permanent teeth with periapical lesions using platelet-rich fibrin versus induced bleeding: a prospective preliminary randomized clinical trial. Clinical Oral Investigations 2026:216. doi: 10.1007/s00784-026-06877-w.

DESIGN
A single-centre, prospective, two-arm parallel randomised clinical trial presented as a preliminary (early-phase) investigation.
CASE SELECTION
Fifty adults presenting with mature permanent teeth where the pulpal status were diagnosed as necrotic with associated periapical lesions were included. The pool of patients was allocated to one of two regenerative endodontic treatment protocols, each containing 25 patients. In the one group, 25 patients underwent a procedure where a canal scaffold was generated by deliberately provoking bleeding from the periapical tissues (induced bleeding, IB). In the second group of patients, an autologous platelet-rich fibrin (PRF) membrane was placed to serve as a biological barrier. A clinical and radiographic review was done at baseline, 6 months and 12 months after treatment completion.
DATA ANALYSIS
Pre-specified endpoints were set to determine firstly, tooth survival and overall treatment success and secondly, periradicular healing through radiographic evaluation. Within- and between-group comparisons were made using the appropriate statistical tests and a statistical significance was set at p < 0.05.


RESULTS
At the one-year mark, 98% of teeth had survived (47/48). Interestingly, survival did not differ meaningfully between the two treatment groups (p = 0.166). Both treatment options produced healing with a statistically significant reduction in periradicular pathology compared with baseline at the six- and twelve-month reviews (p < 0.001). Also, a statistically significant impact was found on the overall success rate at the endpoint (p = 0.022). In the IB group, a 100% success rate was achieved (23/23) compared to 75% in the PRF group (18/24) with a combined overall success of 85.4%.
CONCLUSIONS
Whichever treatment pathway that was followed, all teeth survived the chosen regenerative endodontic procedure after 12 months. The preliminary results indicated that results and clinical outcomes were comparable. Although the IB option showed a higher overall success rate, this finding should be interpreted with caution as the results falls within the early phase clinical evidence framework. Further investigations are required to determine the superiority of one method over the other.