Comparative efficacy of fascia lata allograft, platelet-rich fibrin, and connective tissue graft for peri-implant soft tissue augmentation: a randomized controlled clinical trial

BACKGROUND: Adequate peri-implant soft tissue thickness and keratinized mucosa width are crucial for implant health and aesthetics. Autogenous subepithelial connective tissue grafts (CTG) are the gold-standard for augmenting thin biotypes, but they require a second surgical site. This trial evaluated whether a human fascia lata allograft (FLA) or platelet-rich fibrin (PRF) membrane could comparably enhance peri-implant soft tissue phenotype and serve as less invasive alternatives of CTG. METHODS: Forty-five patients with a thin gingival phenotype (≤ 1 mm thickness) requiring upper anterior implant were randomly assigned to receive soft tissue augmentation with either (1) FLA allograft, (2) PRF membrane, or (3) CTG (control). Interventions were applied concurrently with implant placement in a standardized manner. Gingival thickness (GT) and keratinized tissue width (KTW) were measured at baseline and 6 months using transgingival probing and clinical indices. Labial bone thickness was assessed by cone-beam CT at implant placement and 6 months. RESULTS: Forty-five enrolled patients completed the study. All treatment modalities showed improvements in gingival and bone parameters, with the connective tissue graft consistently demonstrating the greatest gains. The median keratinized tissue width increased to 4.00 mm in the Connective Tissue Graft group, slightly higher than the Fascial Lata Allograft and Platelet-Rich Fibrin groups (3.75 mm). Gingival thickness showed significant increases in all groups, with the Connective Tissue Graft reaching 2.15 mm, followed by Fascia Lata Allograft (1.80 mm) and Platelet-Rich Fibrin (1.55 mm). Labial bone thickness also increased, with the Connective Tissue Graft achieving the highest mean value of 2.300 mm, and after 6 months, significant gains were observed in both this group (p = 0.032) and in the Platelet-Rich Fibrin group (p = 0.044), while Fascia Lata Allograft showed a smaller, non-significant increase. CONCLUSIONS: Both fascia lata allograft (FLA) and PRF improved peri-implant soft tissue parameters, however the connective tissue graft (CTG) remains the gold standard for achieving the greatest thickness and best aesthetic results. FLA is a promising alternative that avoids a second surgical site with comparable outcomes, whereas PRF offers faster healing but lacks the volume necessary for significant tissue modification.