Enhancing Periapical Healing in Endodontic Retreatment Cases: A Clinical Comparative Study Comparing Nano-Hydroxyapatite alone and combined with PRF.

Aim: This study aims to assess bone healing after periapical surgery using nHA and nHA+PRF. Methods: Sixteen patients with periapical lesions in upper or lower anterior teeth with failed endodontic treatments were included. Teeth were divided into two groups of eight. All teeth were retreated in two visits. During the initial visit, the existing root canal filling was removed using ProTaper retreatment files (Dentsply Sirona®). Subsequently, the root canal was irrigated with a 2.5% sodium hypochlorite solution. Following irrigation, the canal was thoroughly dried and filled with a Bi-mix antibiotic paste composed of metronidazole and ciprofloxacin. During the second visit, canals were obturated with gutta-percha and sealer, followed by apicoectomy and root-end filling with MTA. In Group 1; nanohydroxyapatite (nHA) powder was packed into the bony periapical cavity. In Group 2, a mixture of nanohydroxyapatite (nHA) and platelet-rich fibrin (PRF) was packed into the bony periapical cavity. Follow-up visits were scheduled at 1, 3, and 6 months postoperatively for clinical and radiological assessments. Results: At one month follow up, the nHA and nHA+PRF groups showed significantly greater reduction in lesion size. No significant differences were observed between the two groups either at three or six months. Conclusion: nHA+PRF accelerated early bone regeneration compared to nHA alone