L-PRF in Prevention of ORN and MRONJ Following Tooth Extractions;v3.0

Osteoradionecrosis (ORN) is a condition in which necrosis of the jawbone occurs in patients who have previously undergone radiotherapy for head and neck cancer. Medication-Related Osteonecrosis of the Jaw (MRONJ) occurs in patients receiving, or who have received, antiresorptive therapies such as bisphosphonates or denosumab. Both conditions share underlying mechanisms including impaired bone healing, chronic inflammation, and disrupted angiogenesis . Patients in either group face an increased risk of poor healing following tooth extraction, which can result in persistent pain, infection, and progressive jawbone necrosis. These complications profoundly impair patients' abilities to eat and speak, significantly reducing their quality of life.

ORN and MRONJ are extremely difficult to predict, prevent, and manage. Treatment typically requires removal of necrosed bone followed by complex reconstructive procedures that consume significant hospital resources, including materials, staff time, and prolonged hospital stays. Despite these interventions, patients often experience substantial reductions in quality of life. The economic burden on the NHS and responsible trusts is considerable, underscoring the urgent need for improved preventive approaches.

Leukocyte- and platelet- rich fibrin (L-PRF), an autologous leukocyte and platelet concentrate, has demonstrated promising results in promoting soft tissue and bone healing, owing to its angiogenic, anti-inflammatory, and regenerative properties . Its use in dental extractions could mitigate the risk of developing ORN or MRONJ in high-risk populations.

L-PRF is a second-generation platelet concentrate that releases growth factors such as PDGF, TGF-β, and VEGF over an extended period. In vitro studies show that its three-dimensional fibrin matrix continuously releases these factors and cytokines for up to 21 days, which helps regulate inflammation and promote angiogenesis, supporting tissue healing.

L-PRF, a second-generation platelet concentrate, has gained popularity in oral surgery and periodontal procedures (12) with evidence suggesting faster mucosal healing and reduced post-operative complications, because of a slower, continuous release of growth factors when compared to other concentrates in vitro. Furthermore, the leukocytes presented in L-PRF may synthesize several pro- and anti-inflammatory cytokines as well.

However, controlled data on its use specifically for ORN or MRONJ prevention is scarce. Small case series and observational studies suggest improved outcomes, but robust trial data is lacking.

Given the significant morbidity associated with ORN and MRONJ and the lack of proven preventive strategies, evaluating L-PRF in a clinical trial setting is justified. The intervention is autologous and low-risk. Potential benefits include enhanced mucosal healing and reduced incidence of osteonecrosis. Risks are minimal and largely relate to venepuncture or standard surgical procedures. The trial aims to determine feasibility, safety, and early efficacy signals to inform future large-scale trials.

Inclusion criteria

-General Inclusion Criteria (Applies to All Participants)

Age ≥18 years

Requiring extraction of one or more teeth with hopeless prognosis

Capacity to provide informed consent

Ability and willingness to attend all scheduled follow-up visits over 12 months

-Post-Radiotherapy Group - Specific Inclusion

Previous radiotherapy to the head and neck region

Documented radiation dose ≥50 Gy

Radiotherapy records (dose, field, date) must be available

-Antiresorptive Group - Specific Inclusion

Current or prior use of antiresorptive agents (e.g. bisphosphonates or denosumab)

Medication history must be available in medical records

Exclusion criteria

• General Exclusion Criteria (Applies to All Participants)

Inability to maintain adequate oral hygiene due to motor disability

Uncontrolled systemic illness (e.g. uncontrolled diabetes)

Use of anticoagulants, immunosuppressants, or medications known to impair healing

Requirement for surgical (complex) extractions

Enrolment in another clinical trial

Known allergy to anaesthetic agents, L-PRF components, or antibiotics used in perioperative protocol

Anticipated non-compliance with follow-up

-Post-Radiotherapy Group - Specific Exclusion

Previous or current antiresorptive therapy

History of re-irradiation or radiation dose <50 Gy

-Antiresorptive Group - Specific Exclusion

History of head and neck radiotherapy

Neoplastic involvement of the jaws

Active untreated oral infection or pathology at time of planned extraction