A thermosensitive chitosan-based hydrogel for sealing and lubricating purposes in dental implant system

Background Mechanical and biological complications associated with implant systems happen frequently in the clinic. Purpose To develop a chitosan (CS)-based thermosensitive hydrogel for sealing and lubricating purposes in dental implant system. Materials and Methods In this study, a thermosensitive hydrogel made up of CS, beta-glycerophosphate pentahydrate (beta-GP), and povidone-iodine (PVP-I), called CS/beta-GP/PVP-I thermosensitive hydrogel, was fabricated. Three experimental groups with different volume ratios of CS to beta-GP were prepared, namely 16/4, 13/7, and 10/10 groups. The surface topography of the different groups and their physicochemical characteristics were examined by SEM, FTIR, and X-ray diffraction analysis. The cytotoxicity of the hydrogel was examined by CCK-8 test. In vitro antibacterial efficiency was analyzed by the spread plate method. Sealing ability was detected by incubating two-piece implants in Escherichia coli suspension. Lubricating ability of the hydrogel was evaluated by the removal torque test with a calibrated digital torque meter. Results The CS/beta-GP/PVP-I thermosensitive hydrogel was fabricated and showed a highly porous structure under SEM. An in vitro cytotoxicity test demonstrated that 13/7 group displayed no cytotoxicity. Furthermore, all three groups showed obviously antibacterial effects. In the sealing ability test, 16/4 group showed the best sealing ability. The removal torque of 16/4 group and 13/7 group was significantly greater than control group. Conclusions Based on our findings, it could be concluded that the thermosensitive and antibacterial CS/beta-GP/PVP-I hydrogel with sealing and lubricating ability was successfully prepared. The hydrogel had better sealing and lubricating effects when the volume ratio of CS to beta-GP was 16/4.