Preliminary Study Of Skin Secretion Of Chinese Andrias Davidianus Hydrogel Promoting Soft Tissue Sealing Around Implant

Objective: At present,dental implant has become one of the main methods for partial or complete edentulous patients.Although the success rate was high,the incidence of peri-implantitis was19.83%.Peri-implantitis is an inflammation of the soft and hard tissue surrounding implants related to dental plaque.The seal provided by the soft tissue surrounding the implant is important to protect the implant from bacterial contamination and protect bone resorption around the implant.But clinically,it was found that at the early stage of equipping healing abutment and repair abutment,there was no effective soft tissue sealing,and saliva and food residue would enter the gap between soft tissue and abutment,forming milky white dirt on abutment surface.This is obviously bad for the health of the surrounding tissues.Our research group developed the Skin Secretion of Andrias davidianus(SSAD)powder,which was gelatinized by water.SSAD hydrogel had the function of stickiness and promoting skin healing.The viscosity binds the soft tissue around the implant to the abutment,preventing foreign matters from entering the implant.This study will further explore the composition and properties of SSAD hydrogel,its effects on HGF proliferation,titanium plate adhesion and migration and its degradation in vivo,providing a research basis for the in vivo study of SSAD hydrogel promoting soft tissue sealing around implants.Methods: SSAD powders and hydrogels with different particle sizes were observed by scanning electron microscopy and rheological detection.The adhesive strength between SSAD hydrogel and pig gingival tissue was measured.The contents of six growth factors including b FGF,IGF-1,PDGF,EGF,TGF-β and SDF-1 were determined by ELISA.DPPH method was used to investigate the antioxidant activity of SSAD extract.The antibacterial activity of SSAD extract and hydrogel was tested in vitro and in vivo.In addition,human gingival fibroblast HGF was incubated with SSAD hydrogel extract,and the number and morphology of HGF adhered to titanium plates were observed.Transwell migration experiment was used to observe the effect of SSAD hydrogel extract on human gingival fibroblast migration.To evaluate the inflammatory response during the degradation of SSAD hydrogel,the SSAD hydrogel was implanted subcutaneously in rats for HE staining and CD3/CD68 immunofluorescence staining.Results: SSAD hydrogel was a porous network structure.The larger the SSAD powder particles were,the larger the hydrogel was formed.300 mesh SSAD hydrogels G ’and G " are larger than 20 mesh hydrogels.The adhesion of SSAD hydrogel to gingival is greater than that of skin and titanium sheet,and the adhesion of 300 mesh SSAD hydrogel is greater than 100 mesh and 60 mesh.SSAD powder growth factor content was IGF-1(1998 ± 247 ng/g),SDF-1(35.8 ± 5.0 ng/g),EGF(2.8 ± 0.5 ng/g),PDGF(0.9 ± 0.1 ng/g),TGF-β(0.7 ± 0.1 ng/g),b FGF(0.4 ± 0.06ng/g).SSAD extract and hydrogel have certain antioxidant and antibacterial properties.SSAD extract did not promote proliferation of HGF,but could promote its adhesion to titanium plates and migration.SSAD hydrogel can be degraded in vivo and has good biocompatibility.Conclusion: SSAD hydrogel has good adhesion to titanium and gingiva.It can be used to immediately seal the soft tissue around the implant and prevent foreign matters from entering.Its biocompatibility,antioxidant and antibacterial properties as well as its ability to promote the adhesion and migration of human gingival fibroblasts indicate that it has the potential to promote the sealing of soft tissue around implants.