The Antibacterial Composite Resin Reinforced With Sodium Fluoride Loaded Modified Halloysite Nanotubes For Photo-cured Dental Restoration

The dental curing light-curable composite resin will have a certain degree of polymerization shrinkage after curing,which results in a gap between the tooth itself and the filling resin.This gap may be secondary to sputum formation due to bacterial growth.This problem can be solved by imparting a light-cured composite resin.Antibacterial properties are improved.The anti-mite function of fluoride ions has been widely used in dental materials,and is often added directly in the form of sodium fluoride,but this is not conducive to the slow release of fluoride ions from the dental resin,and plays a long-term antibacterial effect.In this paper,in the dental restoration of photocurable composite resin,natural kaolinite halloysite(HNTs)with nanotube structure was added as a filler to the resin,hoping to use its natural tubular structure to support sodium fluoride and achieve fluoride ion.Sustained release,to give the composite resin antibacterial,while using its one-dimensional nanostructures,to enhance the effect of toughening composite resin.In order to improve the dispersibility and interfacial adhesion properties of HNTs in light-cured composites,two surface treatments,silane coupling agent modification and atom transfer radical polymerization(ATRP)graft modification,were used in this thesis.Effect on resin properties.The main work is as follows:HNTs were selected as the filler,and the surface modification was carried out with the silane coupling agent KH570.The optimal feed ratio and hydrolysis reaction time were explored;the HNTs modified by the silane coupling agent were added to BisGMA/TEGDMA at different ratios(w:w-6:4)In the resin system,camphorquinone(CQ)was added as an initiator and DMAEMA was used as a co-initiator.After light curing,three-point bending mechanical properties and cross-section electron microscopy observations were performed.The results showed that:compared with the pure resin system,the spline When the addition amount of HNTs is 2%-3%,the bending strength of the composite resin is increased by about 30%.The HNTs are well dispersed in the resin matrix,and the interface with the resin matrix is well bonded;the amount of HNTs added continues to increase due to the reunion of HNTs.,The depth of cure and mechanical properties are all reduced,but the wear resistance of the resin is significantly improved.The silane coupling agent-modified HNTs were added to the resin system together with the niobium glass powder(maintaining a total amount of 75%).When the amount of HNTs added was 2%,the maximum depth of cure and the maximum bending strength were obtained.2.The PMMA was grafted to the surface of HNTs by ATRP method to obtain HNTs-PMMA,which was added to BisGMA/TEGDMA(w:w=6:4)resin in different proportions,and camphorquinone(CQ)was added as an initiator.DMAEMA was the co-initiator.Three-point bending mechanical properties and electron microscope observations were performed after light curing.It was also found that the dispersion of nanotubes in the resin system was good when the amount of HNTs-PMMA added was 2%-3%.Higher bending strength.Compared with the silane coupling agent-modified HNTs,the HNTs-PMMA composite resin has better performance at the same addition amount,which indicates that the graft modification of PMMA can improve the phase of HNTs and BisGMA/TEGDMA resin more than KH570 modification.Capacitive.3.Sodium fluoride was loaded into HNTs nanotubes by multiple impregnation with sodium fluoride solution and added to BisGMA/TEGDMA(w:w=6:4)resin in different ratios.The addition of camphorquinone(CQ)was used as Initiator,DMAEMA as the co-initiator,was used to perform fluoride ion release,cytotoxicity,and antibacterial activity after light curing.The results show that fluoride ions can be released continuously from HNTs powder and composite resin,but the release rate from the latter is significantly slower than the former;the leukocyte fibroblasts L929 culture was performed using the extract method,and the compound added with fluorine-loaded HNTs was found.The resin had no obvious cytotoxicity;S.aureus was inoculated on the surface of the resin piece and incubated for 18 h before live/dead staining.The observation showed that the pure resin tablet without fluorine-containing filler did not have any antibacterial effect.However,there were a small amount of live bacteria and a large number of dead bacteria on the filler-loaded fluorocarbon nanotube composite resin sheet,demonstrating a good antibacterial potential.The above studies show that the use of surface-modified HNTs as a carrier of sodium fluoride,as a filler added to the light-cured composite resin,is a feasible way to give the composite resin antibacterial performance,and can improve the performance of the composite resin to some extent.