Immediate Implants With or Without a Volume Stable Collagen Matrix: A Randomized Clinical Trial

This randomized clinical trial evaluated soft tissue thickness (STT) around immediate implants with or without soft tissue augmentation using a volume-stable collagen matrix (VCMX). Secondary outcomes included clinical, esthetic, volumetric, and patient-reported outcomes.

Participants received immediate implants in the anterior esthetic zone with (Test) or without (Control) simultaneous VCMX augmentation. Outcomes were assessed before surgery, immediately after surgery, and at 6 and 12 months. The primary outcome was STT. Within- and between-group comparisons were performed using the Friedman rank test and Mann-Whitney U test, respectively. Secondary outcomes included mucosal level (ML), marginal bone level (MBL), esthetic and patient-reported outcomes, and volumetric changes.

Thirty-eight out of 40 patients completed the study. STT was significantly greater in the Test group at all follow-ups (p < 0.05). At 12 months, STT in the Test group increased significantly at 3 mm from the gingival margin (1.85 mm, SE 0.19, p < 0.0001) and non-significantly at 6 mm (1.29 mm, SE 0.24, p = 0.0917), whereas STT in the Control group decreased non-significantly at 3 mm (0.18 mm, SE 0.18, p = 0.6213) and at 6 mm (0.36 mm, SE 0.10, p = 0.1054). ML remained stable in the Test group but showed significant recession in the Control group. Selected esthetic and patient-reported outcomes favored the Test group. MBL did not change significantly over time in either group. Volumetric analysis showed no significant change over time in the Test group, whereas the Control group showed significant shrinkage (p = 0.0201).

VCMX augmentation may improve soft tissue stability around immediate implants.

The study protocol was registered on September 20, 2021 in the ClinicalTrials.gov database (registration number: NCT05081284).