Abstract: Attached gingiva and free gingiva are continuous, both of which are keratinized epithelium, and they are collectively called keratinized gingiva. Attached gingival is tightly attached to alveolar bone, tough texture, strong resistance, and has important significance for periodontal health. Clinically, insufficient or missing attached gingival may cause a series of problems. For example, during chewing, the gingival margin is separated from the dental surface after being rubbed or pulled by muscles, which leads to food residues entering the gingival sulci and causing periodontal destruction. In addition, the edge of the prosthesis and implant will cause pain during mastication. For removable partial denture, it will also affect denture design and patient wearing, and affect the quality of patients life. It can be seen that the deficiency or absence of attached gingival has become a common problem faced by periodontal, prosthesis, implant and other disciplines. For its treatment, there are two main types of methods: autologous soft tissue transplantation and biological replacement materials. The purpose of this review is to explore the characteristics of various therapeutic modalities, provide theoretical basis for clinical work, and provide reference for further research.

Key words: attached gingival, free gingival transplantation, connective tissue flap transplantation, acellular dermal matrix, collagen matrix membrane