Comparative morphological assessment of crosslinked and non-crosslinked xenograft biointegration quality

Relevance. Autografts are nowadays the gold standard for soft tissue augmentation and gingival recession coverage. However, as this method has a number of significant disadvantages, xenografts of various origins are more frequently used in dental practice. The study aimed to conduct a comparative morphological assessment of crosslinked and non-crosslinked xenogenous scaffold biointegration quality at different healing times.Materials and Methods. The study used 108 Wistar rats (54 males, six months old, fat mass 462 ± 20; 54 females, six months old, fat mass 414 ± 7) and randomly divided them into three groups. Group 1 had a xenogenous collagen matrix (Mucograft) placed in the subperiosteal tunnel in the mandibular vestibule area; Group 2 had an acellular dermal collagen matrix (Mucoderm) implanted in the subperiosteal tunnel, group 3 had D-ribose crosslinked xenogenous scaffold (Ossix Volumax) placed in the subperiosteal tunnel.Results. The studied xenogenous materials showed different integration and biodegradation extents. By postoperative day 7, Group 1 (Mucograft) showed a more pronounced inflammation. Non-crosslinked collagen materials had almost completely resorbed by the 30th day of observation, while a crosslinked collagen matrix was detected as homogenous masses. By the 90th day, all groups demonstrated the formation of new connective tissue with different functional characteristics; only Group 3 histologically revealed microfragments of the graft.Conclusion. The study shows that the xenogenous crosslinked and non-crosslinked collagen membranes may promote an increase in soft tissue thickness to a different extent. However, it is essential to improve the available materials to reach an outcome comparable to the autologous soft tissue graft treatment result.