Healing of endodontic lesions with periodontal communication remains challenging and unpredictable, with success rates ranging from 27 to 37% (Hirsch et al., 1979; Skoglund and Persson, 1985) to 77.7% (Kim et al., 2008). The reported incidence of such defects ranges from 3.56% (Grung et al., 1990) to 20% (Song et al., 2013). Various regenerative techniques (Liu et al., 2021) have been advocated, such as guided tissue regeneration (GTR) barrier membranes and grafts in adjunct to endodontic microsurgery to prevent apical migration of junctional epithelium in these cases (Dahlin et al., 1990).

In recent times, autologous platelet concentrates (APCs) have emerged as novel regenerative materials (Liu et al., 2021). APCs might play an important role in wound healing and tissue regeneration via the release of growth factors at high concentrations, including transforming growth factor beta 1 (TGF-b), platelet-derived growth factor (PDGF), epidermal growth factor, insulin-like growth factor (IGF), and vascular endothelial growth factor (VEGF) (Liu et al., 2021).

A positive role of platelet concentrates in periapical surgery has been shown in many studies (Goyal et al., 2011; Taschieri et al., 2012; Singh et al., 2013; Dhiman et al., 2015; Dhamija et al., 2020). Two randomized trials have reported significantly higher rates of periapical healing and gain in clinical attachment levels using APCs (Goyal et al., 2011; Dhiman et al., 2015). However, these studies have assessed the healing using 2D imaging (periapical radiography). Cone-beam computed tomography (CBCT) is a 3D imaging modality that provides better sensitivity and allows more accurate detection of bony defects over the denuded root in sagittal and axial sections (Christiansen et al., 2009; Von Arx et al., 2016a, 2016b; Schloss et al., 2017; Keerthana et al., 2021; Yadav et al., 2022). Only one study has assessed buccal bone formation using CBCT in apicomarginal defects (Yadav et al., 2022).

The postoperative period following periapical surgery should be uncomplicated and comfortable, to allow the patient to restore tissues to a healthy state and prevent unfortunate complications. Beneficial effects of APCs on postoperative quality of life have been highlighted in some clinical studies (Del Fabbro et al., 2012; Taschieri et al., 2014; Angerame et al., 2015; Meschi et al., 2018; Soto-Peñaloza et al., 2020).

Platelet-rich fibrin is a 2nd-generation platelet concentrate introduced by Choukroun et al. (Dohan et al., 2006). Modifications of PRF matrices have been achieved by altering centrifugation protocols. These include the use of leukocyte-rich PRF (L-PRF), advanced PRF (A-PRF), injectable PRF (i-PRF), titanium-prepared platelet-rich fibrin (T-PRF), concentrated growth factors (CGF), and advanced fibrin glue (AFG) (Ezzatt, 2018).

L-PRF and A-PRF are misleading proprietary terms for PRF matrices made using specific machines (Miron et al., 2019a). Studies have advocated using the terminologies PRF High and PRF Medium, depending upon their relative centrifugal forces (RCF) (Kubesch et al., 2019). In vitro studies suggest that lowering RCF results in enhanced levels of leukocytes, platelets, and growth factor release within the fluid PRF-based matrices (Ghanaati et al., 2014; Kobayashi et al., 2016; Fujioka-Kobayashi et al., 2017; Choukroun and Ghanaati, 2018; El Bagdadi et al., 2019). This could have an impact on bone and soft-tissue regeneration (Ezzatt, 2018).

For PRF with high RCF (PRF High; 719 gms), blood is centrifuged at 2700 rpm for 12 min, while for PRF with low RCF (PRF Medium; 222 gms) blood is centrifuged at 1500 rpm for 14 min (Kubesch et al., 2019). Recent research has shown better healing outcomes in periodontal intrabony defects and extraction sockets using PRF with low RCF (Caymaz and Uyanik, 2019; Lei et al., 2020; Starzyńska et al., 2021).

Thus, the aim of the study was to investigate whether there would be a difference in terms of quality of life and healing outcome (2D and 3D) of apicomarginal defects when placing PRF-High and PRF-Medium membranes and clots in bony defects after endodontic microsurgery.