Aim: To test whether or not the use of a collagen matrix (VCMX) results in short-term soft tissue volume increase at implant sites non-inferior to an autogenous subepithelial connective tissue graft (SCTG) and, to evaluate safety and tissue integration of VCMX and SCTG. Methods: In 20 patients with a volume deficiency at single-tooth implant sites, soft tissue volume augmentation was performed randomly allocating VCMX or SCTG. Soft tissue thickness, patient-reported outcome measures (PROMs),

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... safety were assessed up to 90 days (FU-90). At FU-90 (abutment connection), tissue samples were obtained for histological analysis. Descriptive analysis was computed for both groups. Nonparametric tests were applied to test non-inferiority for the gain in soft tissue thickness at the occlusal site. Results: Median soft tissue thickness increased between BL and FU-90 by 1.8mm (Q1:0.5;Q3:2.0) (VCMX) (p=0.018) and 0.5mm (-1.0;2.0) (SCTG) (p=0.0.395) (occlusal) and by 1.0mm (0.5;2.0) (VCMX) (p=0.074) and 1.5mm (-2.0;2.0) (SCTG) (p=0.563) (buccal). Non-inferiority with a non-inferiority margin of 1mm could be demonstrated (p=0.020), the difference of the two group medians (1.3mm) for occlusal sites indicated no relevant, but not significant superiority of VCMX vs. SCTG (primary endpoint). Pain medication consumption and pain perceived were non-significantly higher in group SCTG up to day 3. Median physical pain (OHIP-14) at day 7 was 100% higher for SCTG than for VCMX. The histological analysis revealed well-integrated grafts. Conclusions: Soft tissue augmentation at implant sites resulted in a similar or higher soft tissue volume increase after 90 days for VCMX vs. SCTG. PROMs did not reveal relevant differences between the two groups.