Cross‐Linked Volume‐Stable Collagen Matrix Versus Connective Tissue Graft for Soft Tissue Augmentation at Implant Site. A Non‐Inferiority, Multicenter Randomized Clinical Trial

Aims: To compare the efficacy of cross-linked volume-stable collagen matrix (VCMX) versus connective tissue graft (CTG) to increase buccal peri-implant mucosal thickness (MT) around dental implants. Methods: The present is a parallel, randomized multi-center clinical trial, according to the CONSORT statement. Clinical centers were four Italian periodontal settings. All patients received a soft tissue augmentation procedure, by means of CTG or VCMX. The primary outcome variable was peri-implant mucosal thickness (MT) difference at 12 months follow-up. The statistical unit was the patient. An analysis of covariance was performed for this outcome variable. Secondary outcomes were patient-reported outcome measures (PROMs), complications, variability among operators, and changes in keratinized mucosa width (KMW). Results: A total of 98 patients completed the study, 49 in each group. MT increase was 1.0 ± 0.75 in the CTG group and 0.66 ± 0.58 mm in the VCMX group. CTG showed superior results to VCMX for MT gain (0.37 mm, 95% CI: 0.13–0.61, p = 0.002). In cases of Baseline MT ≥ 2 mm, CTG and VCMX yielded comparable results. VCMX was associated with shorter chair time (diff: 10.0 min; 95% CI: 5.02 to 14.98; p < 0.0001). Patients in the VCMX group experienced fewer days of discomfort (0.46 days, 95% CI: 0.06–0.99, p = 0.05), while no differences were found for final aesthetic and general satisfaction (CTG: 99.28 ± 2.28, VCMX: 98.48 ± 3.92, p = 0.22). Conclusions: Both techniques improved MT, and CTG yielded better outcomes. VCMX was associated with shorter chair time and less postoperative discomfort, but both procedures achieved excellent final patient satisfaction.