Augmentation of soft tissue volume at pontic sites: a comparison between a cross-linked and a non-cross-linked collagen matrix

Abstract

Aim To assess histopathological and histomorphometric outcomes of soft tissue volume augmentation procedures at pontic sites using a volume-stable cross-linked collagen matrix (VCMX) and a non-cross-linked collagen matrix (XCM). Materials and methods In twelve adult beagle dogs, the mandibular premolars and first molar were hemisected and the mesial root extracted. Soft tissue augmentation was randomly performed using VCMX, XCM, or a sham-operated control. Sacrifice was performed after 4, 8, and 26 weeks. Non-decalcified sections were analyzed for histopathologic and histomorphometric measurements at four different levels below the crest (1.5, 2.5, 3.5, and 5.5 mm). Results Group VCMX presented a greater overall amount of soft tissue at all healing time points, more pronounced fibroblast ingrowth, vascularization, and a substantial new collagen deposition. Over time, group XCM demonstrated faster signs of degradation compared with group VCMX. Four weeks after augmentation, group VCMX yielded a higher mean ridge width compared with groups XCM (2.22 mm VCMX, 0.89 mm XCM (at 2.5 mm); 2.05 mm VCMX, 0.80 mm XCM (at 3.5 mm) p < 0.05) and sham (0.59 mm sham (at 1.5 mm); 0.48 mm (at 2.5 mm); 0.44 mm (at 3.5 mm) p < 0.05). After healing periods of 8 and 26 weeks, measurements in group VCMX remained significantly higher compared with group sham both at 8 weeks (levels of 1.5 mm, 2.5 mm and 5.5 mm) and at 26 weeks (levels of 1.5 mm, 3.5 mm and 5.5 mm) (p < 0.05). Conclusion The use of a cross-linked collagen matrix resulted in a greater and more stable ridge width over time compared with control groups. Clinical relevance Soft tissue volume augmentation at pontic sites is more effective when using a cross-linked compared with a non-cross-linked collagen matrix.

Osteoconductive Properties of a Volume-Stable Collagen Matrix in Rat Calvaria Defects: A Pilot Study

“…Nevertheless, the present study confirms existing evidence for the possibility of new bone formation within the VSCM, thus confirming and extending the first reports showing little bone formation inside the VSCM in a dog model [15,16]. VSCM was also reported to be encapsulated by soft tissue without any evidence of mineralization [15,34]. Consistent with the previous observations, VSCM is not an ideal material to support bone formation and might be developed towards a biomaterial supporting chondrogenesis.…”

Functionalization of a Volume-Stable Collagen Matrix Using Liquid Platelet-Rich Fibrin: A Case Report Presenting a New Approach for Root Coverage

“…The functionalized collagen matrix used in this clinical case intends to mimic the natural extracellular matrix of a connective tissue graft, providing a niche for host cells during healing [ 23 , 24 ], which allows cell migration, adhesion, and differentiation, as well as supporting vascular proliferation. Moreover, it has been suggested that the volume-stable collagen matrix has long-term dimensional stability due to its low level of cross-linking degradation [ 25 ]. An in vitro study showed that i-PRF induced cell migration and increased the gene expression of TGF- β mRNA, platelet-derived growth factor (PDGF), and collagen type I [ 26 ].…”

Linear and profilometric changes of the mucosa following soft tissue augmentation in the zone of aesthetic priority: A systematic review and meta‐analysis

“…Nevertheless, both substitutes have a favourable effect and are accompanied by a lower morbidity. VCMX seems even to be more promising than XCM as the latter degrades earlier than VCMX (Moraschini et al., 2020; Naenni et al., 2020). These substitute materials may be suitable for sites, which only require minor thickening of the mucosa, for patients who are pain‐sensitive and for patients who do not consent to the harvesting of soft tissues (Lissek et al., 2020).…”