Preparation And Properties Of Chitosan/β-glycerophosphate Pentahydrate/Nano-silver Thermosensitive Hydrogel In Dental Implant System

Background: The development of science and technology and the maturity of the dental implant technology promote the improvement of dental implant restoration.Dental implants have good biocompatibility,high stability and good chewing efficiency.However,its special mechanical structure would bring many unique mechanical and biological complications of dental implants,and even lead to the implant failure.Therefore,precaution of correlated complications is of great significance for improving the success rate of implantation.Purpose:To reduce complications accompanied with dental implant restoration,this study strives to prepare a novel sealant and lubricant applied in dental implant system as well as evaluate its characteristics,hoping to improve the stability of implantabutment connection and reduce the incidence of micro-leakage between the implant and abutment.Materials and methods: Chitosan(CS),β-glycerophosphate pentahydrate(β-GP)as well as nano-silver(n Ag)were used to prepare the thermosensitive hydrogel in the present study.According to the different volume ratios of CS to β-GP,the hydrogel was divided into 3 experimental groups: 16/4,13/7 and 10/10.Their morphology,elemental composition and chemical properties were analyzed via scanning electron microscopy(SEM),energy-dispersive X-ray spectrometry(EDS)and Fourier transform infrared spectrometer(FTIR).In addition,the stability of implant-abutment connection and the bending strength were investigated to evaluate the role of the thermosensitive hydrogel in dental implant system.Finally,the CCK-8 test and the spread plate method were performed to respectively evaluate the cytotoxicity and in vitro antibacterial effect of this hydrogel.Results: We successfully prepared a highly porous CS/β-GP/n Ag thermosensitive hydrogel.The implant-abutment connection stability experiment demonstrated that the removal torque of experimental groups was significantly greater than control group.The single load-to-fracture test indicated that 16/4 group had the greatest bending strength.All three experimental groups demonstrated no cytotoxicity detected by in vitro cytotoxicity test using specimens from rat bone marrow stromal cells(r BMSCs)and human gingival fibroblast cells(h GFCs).Besides,all experimental groups showed strong antibacterial effects against E.coli,S.aureus and P.gingivalis in antibacterial experiment.Conclusion: We successfully fabricated a non-toxic antibacterial CS/β-GP/n Ag thermosensitive hydrogel.This thermosensitive hydrogel demonstrated better sealing and lubricating abilities between implant and abutment when CS to β-GP reaching a volume ratio of 16/4,meanwhile,the implant-abutment connection stability and the bending strength of dental implant system were the highest.