Peri-implant Soft Tissue Augmentation Using Microneedling With i-PRF vs. Connective Tissue Graft

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.