The Effect of injectable platelet-rich fibrin and low-level laser therapy on graft shrinkage in free gingival grafts: a randomized controlled clinical trial

The aim of this randomized, controlled clinical study was to evaluate and compare the effects of injectable platelet-rich fibrin (i-PRF) applied over free gingival grafts (FGG) on graft shrinkage, root coverage, and postoperative comfort, in comparison with low-level laser therapy (LLLT) and a control group. A total of 48 patients aged 19–41 years with Cairo et al. Gingival Recession Type 1 (RT1) were randomly allocated into control (n = 16), i-PRF (n = 15), and LLLT (n = 17) groups. The primary outcome was graft shrinkage. Secondary outcomes included gingival recession depth (RD), keratinized tissue height (KTH), probing depth (PD), clinical attachment level (CAL), and postoperative outcomes (oedema, erythema, pain, and analgesic consumption). LLLT was applied immediately after surgery and on days 3, 7, and 14 using a 940 nm diode laser (0.21 W, 5 J/cm²). The i-PRF was prepared by centrifuging venous blood at 700 rpm for 3 min and was then applied in gel form onto the graft surface. Graft areas were measured at baseline and at 1, 3, and 6 months using image analysis software. Postoperative oedema, erythema, pain, and analgesic consumption were also evaluated. Graft shrinkage was significantly higher in control subjects than in both treatment groups, and significantly higher in LLLT than i-PRF at all timepoints. Postoperative edema, erythema, and VAS scores showed no significant intergroup differences. Analgesic use was higher in the control group than in i-PRF. KTH values were greater and RD values lower in the i-PRF group compared with the control and LLLT groups. i-PRF reduced graft shrinkage, enhanced root coverage, and improved postoperative comfort, whereas LLLT contributed minimally to graft stability. i-PRF appears to be an effective biological adjunct in FGG surgery. Retrospectively registered at ClinicalTrials.gov (Identifier NCT07303192 Date of registration 20251211).