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Aim To compare the efficacy of adipocyte‐derived dedifferentiated fat (DFAT) cell and adipose‐derived stromal cell (ADSC) sheets for regenerative treatment of intra‐bony periodontal defects. Materials and Methods DFAT cells were obtained using the ceiling culture method and were compared with ADSCs using Cell Counting Kit‐8, colony formation assay, surface antigen identification, and multilineage differentiation assays. DFAT and ADSC sheets were prepared in a cell sheet culture medium. The biological characteristics of DFAT cell and ADSC sheets were compared using haematoxylin and eosin staining, quantitative reverse transcription polymerase chain reaction, and immunofluorescence staining. Micro‐computed tomography and histological staining were used to compare the effects of the two cell sheets on the repair of periodontal intra‐bony defects in rats. Results DFAT cells and ADSCs demonstrated mesenchymal stem cell characteristics. Both cell types were CD29‐, CD90‐, and CD146‐positive and CD31‐, CD34‐, and CD45‐negative. DFAT cells and ADSCs exhibited similar osteogenic and adipogenic differentiation capabilities and colony formation ability. DFAT cells displayed stronger proliferation capabilities compared with ADSCs. Compared with the ADSC sheets, DFAT cell sheets exhibited a higher expression of periodontal‐related genes and proteins and greater ability to regenerate periodontal tissue. Conclusions Our findings suggest that DFAT cell sheets are an ideal seed cell source and form of cell delivery for periodontal intra‐bony defects.

Aim: Periodontitis is an inflammatory, infectious disease of polymicrobial origin that can damage tooth-supporting bone and tissue. Tree shrews, evolutionarily closer to humans than commonly used rodent models, have been increasingly used as biomedical models. However, a tree shrew periodontitis model has not yet been established.Materials and Methods: Periodontitis was induced in male tree shrews/Sprague-Dawley rats by nylon thread ligature placement around the lower first molars. Thereafter, morphometric and histological analyses were performed. The distance from the cemento-enamel junction to the alveolar bone crest was measured using microcomputed tomography. Periodontal pathological tissue damage, inflammation and osteoclastogenesis were assessed using haematoxylin and eosin staining and quantitative immunohistochemistry, respectively.Results: Post-operatively, gingival swelling, redness and spontaneous bleeding were observed in tree shrews but not in rats. After peaking, bone resorption decreased gradually until plateauing in tree shrews. Contrastingly, rapid and near-complete bone loss was observed in rats. Inflammatory infiltrates were observed 1 week post operation in both models. However, only the tree shrew model transitioned from acute to chronic inflammation.Conclusions: Our study revealed that a ligature-induced tree shrew model of periodontitis partly reproduced the pathological features of human periodontitis and provided theoretical support for using tree shrews as a potential model for human periodontitis.