Injectable Platelet-Rich Fibrin Versus Hyaluronic Acid for Thin Gingival Phenotype

Thin gingival phenotype may increase susceptibility to soft-tissue complications in the presence of local anatomical or mechanical risk factors. Minimally invasive injectable approaches such as injectable platelet-rich fibrin (i-PRF) and hyaluronic acid (HA) have been proposed to increase gingival thickness. This randomized split-mouth clinical trial compared repeated i-PRF and non-cross-linked HA injections in adults with a thin mandibular anterior gingival phenotype. Each participant received i-PRF on one mandibular anterior hemi-arch and HA on the contralateral hemi-arch. The primary objective was to compare changes in gingival thickness and keratinized tissue width between the two interventions. Periodontal clinical parameters and injection-related morbidity were assessed as secondary outcomes.