Advanced Platelet-Rich Fibrin and Coronally Advanced Flap for Gingival Recession Treatment

• Background and Rationale Gingival recession is a prevalent anatomical defect characterized by the apical shift of the gingival margin past the cementoenamel junction (CEJ). The Coronally Advanced Flap (CAF) is a reliable and widely applied technique for achieving esthetic root coverage. To overcome the limitations of autogenous grafts, Advanced Platelet-Rich Fibrin (A-PRF) has been introduced as a biologic adjunct. A-PRF is developed based on the Low-Speed Centrifugation Concept (LSCC), providing a porous 3D fibrin scaffold that continuously releases essential growth factors (such as PDGF, VEGF, and TGF-β) to accelerate soft tissue regeneration. This randomized, controlled, parallel-design clinical study aims to evaluate and compare the clinical efficacy of CAF combined with A-PRF versus CAF alone in treating localized gingival recession defects.
• Study Design and Sample Size The required sample size was calculated based on reference data from Padma et al. (2013) to achieve 80% power with a significance level of α = 0.05. Accounting for a 20% anticipated dropout rate, the final sample size was set to 11 defects per group, yielding a total of 22 gingival recession defects. Eligible participants must be 18 years or older, present with Cairo RT1 recession defects in the anterior or premolar region, and exhibit a keratinized tissue width ≥ 1 mm, keratinized tissue height ≥ 2 mm, and probing depth ≤ 2 mm. Defects are randomly allocated into the Test Group (CAF + A-PRF membrane) and the Control Group (CAF alone).
• Clinical and Surgical Procedures

• A-PRF Preparation: At the initiation of the surgical procedure, 10 ml of venous blood is collected using a 24G butterfly needle into sterile glass tubes. Centrifugation is performed intra-operatively using a PRF Duo Quattro machine at 1500 rpm for 14 minutes following the LSCC protocol. The resulting A-PRF clot is carefully compressed in a PRF box to form a membrane with uniform thickness without damaging the cellular structure.
• Surgical Protocol: The surgical intervention follows the standardized CAF technique proposed by Martina Stefanini and Giovanni Zucchelli (2021). Following local anesthesia with Lidocaine 2% and mechanical root debridement, the root surface is chemically conditioned with EDTA 24% (PrefGel). In the Test Group, the intra-operatively prepared A-PRF membrane is stabilized over the defect using 6/0 resorbable sutures, whereas no graft is applied in the Control Group. The flap is then coronally advanced and secured tension-free with suspensory and interrupted sutures.
• Data Collection and Statistical Analysis

• Clinical Assessments: Wound healing is evaluated using the Early Healing Index (EHI) at 1, 2, and 4 weeks post-surgery. Periodontal parameters-including Recession Depth (RD), Recession Width (RW), Clinical Attachment Level (CAL), Gingival Thickness (GT), and Height of Keratinized Tissue (HKT)-are measured at baseline, 1, 3, and 6 months by a calibrated, independent examiner using a UNC-15 probe and customized acrylic stents. The Mean Root Coverage (MRC), Complete Root Coverage (CRC), and Root Coverage Esthetic Score (RES) will also be calculated.
• Statistical Analysis: Data is processed using JASP version 0.96. The Shapiro-Wilk test is utilized to check for normal distribution. Intra-group variations over time are analyzed using the Friedman test followed by Conover post-hoc analysis with Bonferroni correction. Inter-group differences are assessed using the Mann-Whitney U test, with statistical significance strictly defined as p < 0.05.

Inclusion criteria

• Patients aged 18 years or older.
• Presence of 1 to 2 gingival recession defects requiring treatment, classified as RT1 (Cairo 2011).
• Gingival recession defects located in the anterior or premolar regions of the maxilla or mandible.
• Gingival thickness ≥ 1 mm. Keratinized tissue width ≥ 2 mm. Probing depth ≤ 2 mm.
• Good oral hygiene, demonstrated by a mean Gingival Index (GI) ≤ 1 and a mean full-mouth Plaque Index (PI) ≤ 1.

Exclusion criteria

• Patients with systemic diseases affecting wound healing (e.g., diabetes mellitus, coagulation disorders).
• Pregnant or lactating women.
• Patients with a smoking habit.
• Teeth with interproximal bone loss.
• Severely malpositioned teeth.
• Presence of caries or cervical restorations at the experimental site.
• History of previous periodontal surgery at the selected sites.