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.

RESULTS

From 6 months to 3 years, mRC decreased by 6.7% in the control arm and 7.5% in the test arm (p > 0.05). Over 90% of treated sites maintained a stable gingival margin (≤ 0.5 mm shift). No significant inter-group differences were found for volumetric, aesthetic or PROM outcomes. Ultrasonography revealed increased tissue elasticity in treated sites. In contrast, untreated contralateral sites showed progressive gingival recession and increased hypersensitivity (p < 0.001).

CONCLUSION

Both VCMX treatments demonstrated stable clinical and ultrasonographic outcomes over 3 years, while untreated sites showed signs of soft-tissue deterioration.