Gingival morphology after using Fibro-Gide and FibroMATRIX collagen matrices and connective tissue grafts around dental implants

BACKGROUND: Free connective tissue grafts (FCTGs) from the maxillary tuberosity and hard palate and their collagen matrix substitutes are widely used in clinical practice to increase the volume of soft tissue around dental implants. However, a comparative histological evaluation of their clinical use has not been performed. AIM: The aim of the study was to identify structural differences in gingival tissue in the area of use of Fibro-Gide and FibroMATRIX collagen matrices and FCTGs by histology and morphometry. MATERIALS AND METHODS: Morphometry of FCTG biopsies was performed prior to FCTG use around dental implants. Tissue sections were stained with hematoxylin and eosin, van Gieson stain, and Masson’s stain. A similar procedure was used for morphometry of biopsies from the regeneration areas 3 months after surgery, with additional immunohistochemical staining with anti-CD45 and anti-CD68 antibodies. RESULTS: Prior to transplantation of palatal FCTGs, the relative fat volume was (9.8±4.8)%, which was statistically significantly greater than (7.2±1.1)% for tuberosity FCTGs. The relative number of blood vessels was greater in palatal FCTGs compared with tuberosity FCTGs: (2.3±0.6)% versus (1.2±0.6)%, respectively. Three months after transplantation, the highest relative amount of connective tissue was found in the tuberosity FCTG group: (68.8±2.3)%. The lowest amount was reported with the FibroMATRIX material: (50.1±1.7)%. The largest relative vascular area was reported in palatal FCTG and Fibro-Gide groups: (2.7±0.2)% and (2.0±0.2)%, respectively. The smallest area was reported in tuberosity FCTG and FibroMATRIX groups: (1.0±0.2)% and (1.0±0.1)%, respectively. CONCLUSION: The structure of the regenerated gingiva inherits some morphological characteristics of the FCTG associated with the characteristics of the graft source: the palate or the tuberosity. Therefore, a larger vascular area and greater fibroblast counts were observed both in the original palatal FCTG and in the regenerate obtained after graft use. The Fibro-Gide and FibroMATRIX collagen matrices used as FCTG substitutes were not completely resorbed after 3 months and induce macrophage, leukocyte and lymphocyte infiltration. The histologic data obtained may clarify the clinical and aesthetic differences in the results obtained using autogenous FCTGs and their collagen matrix substitutes. © 2024, Human Stem Cell Institute. All rights reserved.