Stability of Root Coverage Outcomes After Soft-Tissue Augmentation With a Collagen Matrix With or Without rhPDGF-BB: A 3-Year Triple-Blinded, Randomised, Placebo-Controlled Trial

Aim: To evaluate the 3-year stability of root coverage outcomes following treatment with a coronally advanced flap (CAF) and a volume-stable, cross-linked xenogeneic collagen matrix (VCMX), either soaked in recombinant human platelet-derived growth factor-BB (rhPDGF, test arm) or sterile saline (control arm). Methods: Of the original 30 participants in the triple-blind, randomised, placebo-controlled trial, 26 were available for follow-up at 1 and 3 years. The primary outcome was mean root coverage (mRC) at 3 years compared to the 6-month results. Secondary outcomes included complete root coverage, keratinised tissue width, gingival thickness, volumetric and aesthetic changes, patient-reported outcome measures (PROMs) and ultrasonographic tissue properties. Untreated contralateral teeth were also assessed. Conclusion: Both VCMX treatments demonstrated stable clinical and ultrasonographic outcomes over 3 years, while untreated sites showed signs of soft-tissue deterioration.