This randomized controlled clinical trial aims to evaluate a minimally invasive technique for peri-implant soft tissue augmentation using microneedling combined with injectable platelet-rich fibrin (i-PRF) compared with the current gold-standard connective tissue graft (CTG). Patients with thin peri-implant soft tissue requiring implant second-stage surgery in the esthetic zone will be randomly assigned to receive either CTG harvested from the palate or a series of microneedling and i-PRF treatments. Clinical outcomes including mucosal thickness, keratinized tissue width, peri-implant health parameters, volumetric soft tissue changes, esthetic outcomes, and patient-reported measures of pain and satisfaction will be evaluated during follow-up. The study aims to determine whether microneedling with i-PRF can provide comparable soft tissue augmentation while reducing patient morbidity associated with connective tissue graft harvesting.

Peri-implant soft tissue quality is a key determinant of implant health, long-term stability, and esthetic outcomes. Adequate peri-implant mucosal thickness and keratinized tissue width contribute to the maintenance of peri-implant health, while thin soft tissue phenotypes have been associated with increased risk of recession, discomfort during oral hygiene procedures, and peri-implant tissue complications. Connective tissue grafting (CTG) remains the gold standard for peri-implant soft tissue augmentation; however, it requires harvesting autogenous tissue from a secondary donor site, resulting in increased surgical morbidity, postoperative discomfort, and longer treatment time.

Recent regenerative approaches have focused on the use of injectable platelet-rich fibrin (i-PRF), an autologous blood-derived concentrate rich in platelets, leukocytes, fibrin, and growth factors that promote angiogenesis, collagen formation, and soft tissue healing. Microneedling is a minimally invasive technique that creates controlled micro-injuries within the soft tissues, stimulating collagen production and enhancing the penetration and biological effects of regenerative agents. Preliminary evidence suggests that combining microneedling with i-PRF may enhance peri-implant soft tissue thickness and quality while minimizing patient morbidity.

This study is designed as a prospective, parallel-arm randomized controlled clinical trial comparing microneedling combined with injectable platelet-rich fibrin (MN+i-PRF) with connective tissue grafting (CTG) for peri-implant soft tissue augmentation during implant second-stage surgery. Approximately 24 eligible participants presenting with thin peri-implant soft tissue phenotype in the esthetic zone will be randomly allocated in a 1:1 ratio to either the test or control group. Allocation concealment will be performed using computer-generated randomization and sealed opaque envelopes. Outcome assessors will be blinded to treatment allocation.

Participants in the control group will undergo peri-implant soft tissue augmentation using a subepithelial connective tissue graft harvested from the palate and stabilized at the buccal aspect of the implant site. Participants in the test group will receive microneedling using a sterile automated microneedling device followed by injection of autologous i-PRF into the peri-implant mucosa. The test intervention will be performed at implant uncovery and repeated at 2-week and 4-week follow-up visits to maximize regenerative effects.

The primary outcome measure will be the change in peri-implant mucosal thickness from baseline. Secondary outcome measures will include keratinized tissue width, peri-implant probing depth, bleeding on probing, volumetric soft tissue contour changes assessed through intraoral scanning, Pink Esthetic Score (PES), and patient-reported outcome measures including postoperative pain and treatment satisfaction. Clinical and patient-centered outcomes will be evaluated at predefined follow-up intervals extending up to 9 months after treatment.

The objective of this study is to determine whether microneedling combined with i-PRF can provide peri-implant soft tissue augmentation outcomes comparable to connective tissue grafting while reducing treatment invasiveness and patient morbidity. The findings may contribute to the development of minimally invasive regenerative approaches for peri-implant phenotype modification and esthetic enhancement.

Inclusion Criteria:

• Systemically healthy adults (Between 18 and 65) with one or more dental implants requiring second-stage surgery in the esthetic zone (Anteriors and Premolars).
• Thin soft tissue phenotype: mucosal thickness or KTW <2 mm buccally.
• Stable osseointegrated implant, adequate restorative space, and healthy adjacent teeth.
• Good oral hygiene (PI ≤10%), with peri-implant maintenance.
• Signed consent + willingness for 1-year follow-up.

Exclusion Criteria:

• Heavy smokers (≥10 cig/day); light smokers only if reduced.
• Systemic/healing issues: uncontrolled diabetes, immunocompromise, bleeding disorders, anticoagulants, steroids.
• Pregnancy or breastfeeding.
• Active infection (periodontal or peri-implant).
• No residual keratinized mucosa on buccal side.
• Previous graft/augmentation at the site or recent surgery (<6 months).
• Allergies to anesthetics/materials.
• Non-compliance with instructions or follow-up.

Outcome assessors responsible for clinical measurements, peri-implant soft tissue evaluations, Pink Esthetic Score assessment, intraoral scan analysis, and data collection will be blinded to treatment allocation. Due to the nature of the interventions, blinding of participants and care providers is not feasible.