Volumetric soft tissue alterations in the early healing phase after peri- implant soft tissue contour augmentation with a porcine collagen matrix versus the autologous connective tissue graft: A controlled clinical trial

Aim This study evaluates the early volumetric changes after buccal soft tissue contour augmentation around implants with a porcine collagen matrix (CM) vs. the subepithelial connective tissue graft (SCTG) from the palate. Materials and methods 14 patients were enrolled after early implant placement with simultaneous contour augmentation and persistent buccal tissue deficits. At implant exposure, buccal soft tissues were thickened with the CM (n = 7) or the SCTG (n = 7). Impressions were taken before and after surgery, after ten days, one, three and six months. Impressions were digitized and augmented regions 3D evaluated (soft tissue volume (mm(3), %)/thickness (mm)). Results Volume increase (mm(3)) after 6 months was 19.56 +/- 8.95 mm(3) (CM) and 61.75 +/- 52.69 mm(3) (SCTG) (insignificant, p = .058). In percentage, this was a volume loss of the initially augmented soft tissue volume (100%) of 81.76% in the CM group and 56.39% in the SCTG group (6 months). The mean soft tissue thickness increase (mm) in the buccal contour after 6 months was 0.30 +/- 0.16 mm (CM) and 0.80 +/- 0.61 mm (SCTG) (insignificant, p = .071). Conclusion The early healing phase is associated with a significant volume loss of the soft tissues. The SCTG shows insignificant superiority compared to the CM.