Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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. TRIAL REGISTRATION: 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.