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

## TL;DR

This study compares two methods for increasing gum tissue thickness around dental implants and finds that one method is faster and less uncomfortable, though slightly less effective.

## Contribution

The study introduces a novel comparison of cross-linked collagen matrix versus connective tissue graft in soft tissue augmentation for dental implants.

## Key findings

- CTG showed a greater increase in mucosal thickness compared to VCMX.
- VCMX was associated with shorter chair time and fewer days of postoperative discomfort.
- Both techniques achieved high patient satisfaction with no significant difference in aesthetics.

## Abstract

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.

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).

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).

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.