Adjunctive extended platelet-rich fibrin enhances clinical and esthetic outcomes of the VISTA technique in RT1 gingival recession: A randomized controlled clinical trial

Technical Summary: Adjunctive Extended Platelet-Rich Fibrin in the VISTA Technique for RT1 Gingival Recession

Problem Statement
Gingival recession, particularly in the aesthetic zone involving anterior teeth, presents significant functional and aesthetic challenges, often leading to root sensitivity and patient anxiety. While the Coronal Advanced Flap (CAF) with Connective Tissue Graft (CTG) is considered the gold standard for root coverage, it is associated with increased patient morbidity, the need for a secondary donor site, and potential complications such as flap dehiscence. Minimally invasive alternatives, such as the Vestibular Incision Subperiosteal Tunnel Access (VISTA) technique, have been developed to reduce trauma and preserve papillary integrity. However, the VISTA technique alone may yield variable soft tissue thickness and phenotypic outcomes. Furthermore, while Platelet-Rich Fibrin (PRF) is a known adjunct that promotes healing, its rapid degradation (within 10–14 days) limits its long-term regenerative capacity. There is a need to evaluate whether "Extended-PRF" (e-PRF), a biomaterial with prolonged resorption properties (4–6 months), can enhance the clinical and esthetic outcomes of the VISTA technique for Cairo RT1 recession defects.

Methodology
This study was a single-center, randomized, controlled, single-blind clinical trial conducted at Bapuji Dental College and Hospital between August 2023 and April 2024.

• Participants: 20 systemically healthy patients (aged 20–55) with 46 RT1-type gingival recession sites were enrolled. Participants had a Plaque Index (PI) score < 1.9. Smokers, pregnant/lactating females, and those unavailable for follow-up were excluded.
• Study Design: Sites were randomly allocated into two groups (1:1 ratio):
  • Group I (Control, n=23 sites): Treated with the VISTA technique alone.
  • Group II (Test, n=23 sites): Treated with the VISTA technique augmented with an e-PRF membrane.
• Surgical Protocol:
  • A vertical vestibular incision was made to create a subperiosteal tunnel using specialized elevators.
  • In Group I, the tunnel was left empty, and the mucogingival complex was coronally repositioned and sutured.
  • In Group II, an e-PRF membrane was prepared by mixing heated Platelet-Poor Plasma (PPP) albumin gel with Concentrated PRF (C-PRF) to extend resorption time. This membrane was inserted into the tunnel prior to coronal repositioning and suturing.
• Parameters: Clinical parameters were recorded at baseline and 6 months post-operatively. These included Recession Depth (RD), Recession Width (RW), Probing Depth (PD), Clinical Attachment Level (CAL), Width of Keratinized Gingiva (WKG), and Gingival Thickness (GT).
• Outcomes: Percentage Root Coverage (%RC) and Root Coverage Esthetic Scores (RES) were calculated at 6 months. Gingival phenotype (thin vs. thick) was assessed using the probe transparency method.
• Statistical Analysis: Data were analyzed using SPSS. Intra-group comparisons utilized paired t-tests, while inter-group comparisons used independent t-tests and Chi-square tests for phenotype distribution. Significance was set at p < 0.05.

Key Results
All 20 participants completed the 6-month follow-up with no dropouts or surgical complications.

• Recession Parameters: Both groups showed statistically significant improvements in RD, RW, and CAL from baseline to 6 months (p < 0.05). However, Group II (VISTA + e-PRF) demonstrated a significantly greater reduction in RD compared to Group I (p < 0.05).
• Soft Tissue Augmentation:
  • Gingival Thickness (GT): Group II showed a statistically significant increase in GT (from 0.82 ± 0.16 mm to 1.52 ± 0.48 mm), whereas Group I showed no significant change (0.74 ± 0.42 mm to 0.83 ± 0.17 mm).
  • Width of Keratinized Gingiva (WKG): Group II exhibited a significant gain in WKG (p = 0.002), while Group I showed no significant change.
• Root Coverage and Esthetics:
  • %RC: Group II achieved a significantly higher mean percentage of root coverage (82.67 ± 24.84%) compared to Group I (67.83 ± 32.17%) (p = 0.041).
  • RES: Group II achieved a superior Root Coverage Esthetic Score (8.88 ± 1.48) compared to Group I (7.04 ± 3.36) (p = 0.04).
• Phenotype Conversion: At 6 months, Group II showed a significant conversion from thin to thick gingival phenotype (95.6% thick vs. 4.3% thin), whereas Group I showed no significant change in phenotype distribution (p < 0.001 for Group II inter-group comparison).

Key Contributions
The study provides clinical evidence that the adjunctive use of e-PRF with the VISTA technique offers superior outcomes compared to the VISTA technique alone for RT1 recession defects. Specifically, the study demonstrates that e-PRF:

1. Enhances soft tissue thickness and width of keratinized gingiva, which are critical for long-term stability.
2. Facilitates a higher percentage of root coverage and better esthetic scores.
3. Promotes the conversion of thin gingival biotypes to thick biotypes, addressing a common limitation in minimally invasive root coverage procedures.
4. Serves as an autologous, chairside biomaterial that avoids the morbidity associated with connective tissue grafts.

Significance and Claims
The authors conclude that the slow-resorbing matrix of e-PRF, combined with its sustained release of growth factors, acts as an effective bioactive barrier membrane. This property appears to support cell migration and proliferation over a longer duration (4–6 months) compared to standard PRF, leading to superior soft tissue augmentation and esthetic results. The study positions e-PRF as a promising autologous biomaterial to enhance minimally invasive root coverage procedures, particularly in cases involving thin biotypes where tissue augmentation is challenging.

The authors acknowledge limitations, including a relatively short follow-up period (6 months), a modest sample size, and the lack of histological analysis. Consequently, they modestly suggest that while the results are encouraging, further randomized controlled trials with larger sample sizes and longer follow-ups are necessary to fully validate these findings. The study does not claim e-PRF is a replacement for the gold standard CTG but rather a superior alternative to VISTA alone for specific clinical scenarios.