Femtosecond laser microgrooves combined with CGF promote implant transgingival integration through Smad3/JunD/TIMP-1 pathway and its immune regulatory mechanism
In implant repair, early soft tissue healing can form a stable barrier to prevent implant loosening failure caused by bacterial invasion. The adhesion between the epithelium surrounding the implant and the surface of the titanium implant is achieved through hemidesmosomes. The connective tissue interface is composed of fibroblasts and collagen fibers with poor vascular structure and rich scar tissue like structure, which are parallel to the surface of titanium implants. In natural teeth, the collagen fibers on the surface of the dentin are vertical. The surface structure and coverage of biological factors at the neck ring of the implant are important factors affecting the soft tissue adhesion around the implant. The microgroove structure can alter the fiber pathway at the junction of the abutment and soft tissue, and regulate the phenotypic transformation of macrophages; Concentrated growth factor (CGF) derived from blood can promote the healing of gingival soft tissue after surgery and regulate immune response. However, the combined effect of microgrooves and CGF has not been studied yet. We use femtosecond laser to etch micro grooves on the neck ring of the implant, and infiltrate CGF into the neck ring of the implant micro groove through immersion, so that the micro groove structure works in combination with CGF. The implant is implanted into the alveolar bone of beagle dogs, and the color, shape, texture, and gingival margin position of the gingiva are checked for relevant clinical data measurement. Then, the implant is harvested together with the surrounding soft and hard tissues to preserve the ability of soft tissue attachment and recognition of biological width, for histological preparation and analysis. This study delves into the phenomenon of promoting implant transgingival integration, anchoring collagen fibers vertically, and making connective tissue adhesion more stable and firm, as well as its immune regulatory mechanism. This study constructed an implant with a micro groove neck ring and concentrated growth factor (CGF) derived from blood, clarifying the relationship between the binding of the micro groove structure in the neck of the implant and the sealing effect of the connective tissue around the implant. It revealed that the micro groove structure and CGF can promote M2 polarization of macrophages in the gingival connective tissue, and clarified that the morphology of the micro groove in the neck of the implant combined with CGF can promote the phenomenon of implant transgingival binding. Overall design: Comparative gene expression profiling analysis of RNA seq data of gingival tissue around different types of implants, including smooth neck ring implants, micro groove neck ring implants, and micro groove neck ring combined with CGF implants.