Comparing two types of platelet-rich fibrin membranes in the management of dehiscence defects with simultaneous implant placement in the posterior mandible: a randomized controlled trial

Abstract

Alveolar ridge resorption after tooth extraction may compromise implant placement and frequently necessitates guided bone regeneration (GBR). Platelet-rich fibrin (PRF) is widely used in oral surgery; extended PRF (e-PRF) has been proposed to prolong growth factor availability and membrane stability. This randomized clinical trial compared PRF and e-PRF membranes combined with bovine xenograft for horizontal ridge augmentation with simultaneous implant placement in the posterior mandible. Twenty patients with posterior mandibular ridge deficiencies (residual ridge width 4–6 mm) were randomized (1:1) to receive xenograft + PRF (control, n = 10) or xenograft + e-PRF (study, n = 10) at the time of implant placement. Primary outcome: horizontal bone width gains at 6 months assessed by standardized CBCT measurements 1 mm apical to implant platform. Secondary outcomes: implant stability quotient (ISQ) at baseline and 6 months, postoperative pain (VAS), and edema. Sample size was calculated to detect the expected difference in ISQ change with 80% power and α = 0.05. Statistical tests included paired and independent t-tests, repeated measures analyses, and non-parametric tests where appropriate. Significance threshold was p ≤ 0.05. Twenty patients (30 implants; 8 males, 12 females; mean age 40.2 ± 5.3 years) completed the study. Baseline characteristics and residual ridge widths were similar between groups. Implant stability (ISQ) increased significantly within both groups from baseline to 6 months (p < 0.001) but did not differ between groups at either time point (baseline p = 0.622; 6 months p = 0.263). Postoperative pain and edema followed similar, transient patterns in both groups (no significant between-group differences). At 6 months, horizontal bone gain was significantly greater in the e-PRF group (mean gain 2.28 ± 0.79 mm) than in the PRF group (0.75 ± 0.18 mm), p < 0.001. In this randomized clinical trial, both PRF and e-PRF combined with bovine xenograft and simultaneous implant placement produced favorable clinical outcomes, while e-PRF provided superior horizontal bone gain at 6 months. Further larger and longer-term trials with prospective registration are recommended to confirm these findings. The study protocol approved by the Institutional Review Board of the Faculty of Dentistry, Alexandria University, Egypt (IRB No. 0936-06/2024–00010556). This trial was retrospectively registered at ClinicalTrials.gov (ID: NCT07164417, Date of registration: 04/09/2025; https://clinicaltrials.gov/study/NCT07164417). All participants provided written informed consent before enrollment.