The Efficacy of Leukocyte-Platelet-Rich Fibrin in Combination with Sub-Epithelial Connective Tissue Graft in Peri-Implant Soft Tissue Augmentation: A Randomized Controlled Clinical Trial

The aim of the current study is to assess and compare the efficacy of the leukocyte-platelet-rich fibrin (L-PRF) in combination with sub-epithelial connective tissue graft (SCTG) and SCTG only in promoting aesthetic results and strengthening the state of the soft tissue surrounding implants.

A parallel-arm randomized controlled clinical trial was used for this investigation. A total of 120 patients who had missing teeth with a thin gingival biotype [less than 1.5 mm] were included in this study. The patients of Group I were treated with PRF and SCTG during second-stage implant surgery, while the patients of Group II were treated with SCTG only. Treatment outcomes included the assessment of the width and thickness of the keratinized tissue at the baseline, 3 and 6 months postoperatively; pro- and anti-inflammatory cytokines (IL-1β, TNF-α, and IL-4) in the peri-implant crevicular fluid on the 1st, 7th and 30th days after surgical procedure; swabs from the surface of postoperative wounds of the mucous membrane on days 3, 5, 7, and 10; Pink aesthetic score (PES) 6 months after prosthesis placement; and laser Doppler flowmetry on days 1, 7, and 14 after augmentation.

Patients who received L-PRF+SCTG had a significant increase in keratinized tissue thickness (KTT) (p = 0.08) than those who received SCTG only (KTT 1.86 ± 0.17 Vs 1.48 ± 0.15) 6 months after surgery. The mean (±SD) of PES was found to be 13.1 (±0.02) for Group I and 11.3 (±0.08) for Group II. The cytology, LDF, and local immunoassay analysis demonstrated faster epithelialization and better revascularization in Group I.

The use of L-PRF and SCTG is an effective method in augmenting peri-implant soft tissue and improving gingival biotype and aesthetic outcomes, which would help overcome complications and increase patients’ satisfaction.

ISRCTN27670172