Platelet-rich fibrin/anorganic bovine bone mineral complex as grafting materials in endodontic microsurgery with a large lesion size: study protocol for a randomised controlled trial

Introduction Endodontic microsurgery is a treatment of last resort for preserving natural teeth. According to radiographic evaluation, the percentage of complete healing after endodontic microsurgery is only 74.3%. The use of regenerative techniques in endodontic microsurgery for large lesions (>10 mm diameter) is therefore recommended. The most frequently used bone graft in endodontic microsurgery is anorganic bovine bone mineral (ABBM) but this only has an osteoconductive effect. Thus, when platelet-rich fibrin (PRF), a reservoir of growth factors, is used together with ABBM, it increases the regenerative effect. This study is devoted to comparing the clinical outcomes of PRF with/without ABBM as grafting biomaterials in endodontic microsurgery cases with large lesion size to provide some valuable reference data for dentists. Methods and analysis Sixteen patients who are in need of endodontic microsurgery will be recruited. The patients will be randomly assigned to one of two groups: an experimental group, treated with PRF/ABBM complex and collagen membrane, and a control group, treated with ABBM and collagen membrane. Clinical examination including percussion, mobility testing and presence/absence of sinus will be recorded at 7 days, and at 3, 6 and 12 months after endodontic microsurgery. A Visual Analogue Scale will be used by the patients to evaluate pain at 1, 3 and 7 days after endodontic microsurgery. Routine paralleling radiographs will be obtained before and at 3, 6 and 12 months follow-up after endodontic microsurgery. Cone-beam CT (CBCT) scans will be obtained at the 12-month follow-up. Bone formation will be evaluated according to CBCT and paralleling radiographs. The study execute time including follow-ups last from 1 June 2021 to 31 December 2024. Ethics and dissemination This study received approval from the Ethics Committee of Peking University School and Hospital of Stomatology. The results will be disseminated through scientific journals.