Background Functional reconstruction of periodontal soft tissue is a major focus in both clinical and basic research within the field of dentistry. However, standardized small-animal models that accurately recapitulate clinical periodontal soft tissue defect remain limited, hindering the development of the graft materials. This study aimed to establish a standardized, minimally invasive and reproducible rat model of periodontal soft tissue defect for systematic in vivo assessment of soft tissue regeneration. Methods The anatomical characteristics of the maxillary and mandibular anterior labial regions and the hard palate in rats were comprehensively assessed to identify optimal recipient and donor sites. Based on these findings, a standardized 4 × 2 mm soft tissue defect was created in the maxillary anterior labial region and reconstructed using autograft, xenograft or left untreated as a control. The healing process was evaluated through sequential clinical observation, HE staining, Masson’s trichrome staining and immunohistochemical analyses. Results The results demonstrated that this model enabled consistent defect creation with low complication rates and high reproducibility. Distinct yet clinically relevant healing patterns were observed among different treatment groups, closely resembling those reported in human periodontal soft tissue reconstruction. The model allowed dynamic evaluation of the quality of healing, tissue integration, materials degradation, angiogenesis and immune response of periodontal soft tissue regeneration. Discussion This model provides a robust and translationally relevant in vivo platform for the mechanistic assessment of soft tissue graft materials. It facilitates systematic investigation of biological responses during soft tissue regeneration and supports early-stage screening and optimization prior to large-animal studies and clinical translation.
Huang et al. (Mon,) studied this question.