Post-operative histogenesis in the allogeneic dura mater placement area in a laboratory rat experiment: laboratory and histomorphological research

Abstract

Relevance. Gum recession is a pathology often encountered both in Russia and worldwide. Modern surgical methods allow for the complete elimination of recession signs when adequately choosing strategy, tactics, methodology and surgical treatment protocol; for complication prevention and stable long-term outcome. Autograft and allogeneic dura mater as a grafting material for creating/increasing the volume of the attached gingiva in recession treatment have comparable results in all clinical indications. The reason for result stability and the absence of relapse is poorly studied; the data are scarce and do not give a full understanding. In the scientific literature, we did not encounter histological tissue composition analysis in the graft placement area. In recession coverage, the graft is partially placed subperiosteally (in the tooth root area) and partially in the thickness of the soft tissues of the gum. Purpose. The study aimed to determine the histological composition of tissues in the dura mater placement area, to compare with the control group without a graft, and to assess follow-up changes in the graft and surrounding tissue reaction as a result of cellular-level surgery.Material and methods. A laboratory histomorphological examination involved 60 laboratory rats. All underwent surgery adequate to gum recession surgical treatment technique: the control group had no graft, and the study group had allogeneic dura mater. The samples were collected on the 3rd, 7th, 14th, 28th, 90th and 107th days after surgery.Results. In all cases, the tissue complex regenerated, and the reaction to the operation was the same. The plastic material replacement was at the same period. Bone tissue replaced subperiosteally placed graft, connective tissue intragingivally. Gingival biotype thickening was considerably due to the surgical trauma, less – from the graft material. Allogeneic dura mater stimulated earlier ossification.Conclusion. In all cases, the use of grafting material for surgical gum recession coverage is justified if placed subperiosteally, forming a full-thickness mucoperiosteal flap surgically (with a scalpel) to preserve the cambium periosteum on the flap. Bone volume and buccal cortical plate reconstruction/ regeneration support soft tissues of the newly formed ligament of the tooth and prevent recurrent recession formation. The formation of bone and connective tissues in the dura mater placement area determines the result stability of gingival recession surgical treatment and a long-term favourable prognosis without complications and relapse.