Tissue integration and vascularization of volume collagen matrices and connective tissue grafts following...

This study aimed to histologically reanalyze tissue integration and vascularization of volume collagen matrices (VCMX) and subepithelial connective tissue grafts (SCTG) at 3 and 4 months following peri-implant soft tissue augmentation. Peri-implant soft tissue augmentation was performed with VCMX or SCTG and biopsies were harvested at 3 and 4 months. Secondary analyses included descriptive histology, blood vessel count and tissue composition [remaining matrix, peri-implant connective tissue containing 3 different components (collagen bundles, elastic connective tissue and loose connective tissue), elastic fibers and background]. A total of 21 samples were analyzed (VCMX: 6/9 biopsies at 3/4 months; SCTG: 6 biopsies at 3 months). Compared to SCTG, VCMX sites displayed fewer and smaller blood vessels within denser tissue. Collagen bundles in VCMX were thicker, whereas SCTG sites displayed a looser tissue structure. The proportion of elastic connective tissue were 22.5% (VCMX/3 months), 32,7% (VCMX/4 months) and 17.4% (SCTG/3 months). Additionally, VCMX samples at 3 months also showed the highest proportion of elastic fibers (10,7%). Peri-implant soft tissue augmentation with VCMX resulted in reduced vascularization but increased tissue density compared to sites augmented with SCTG.