Study On The Preparation Of Multifunctional Silica-based Fillers And Their Effect On The Properties Of Dental Resin Composites

Dental resin composites（DRCs）have become the material of choice for clinical caries restoration by virtue of its excellent physical and chemical properties,good aesthetic effect and convenient operation.In addition,it has great potential for development in terms of antibacterial and remineralization self-restoration functions.However,DRCs often suffer from fracture and secondary caries during oral service,which eventually lead to restoration failure.To address the above problems,this project constructs a functional nanocomposite filler that integrates antibacterial and reinforcing properties,and further compounds silane-modified barium glass powder（BGP-M）with X-ray blocking properties to build a multifunctional DRCs with antibacterial,high strength and blocking properties in a dual-filler filling,and the specific research contents and results are as follows.1.Design and construction of folded mesoporous SiO₂-loaded ZnO nanoparticles（ZnO@WMS）.In this study,ZnO@WMS was synthesized in one step by a simple and efficient"one-pot"process,and the effect of ZnO@WMS filler structure and its filling amount（3 wt%,5wt%,7 wt%,10 wt%）on the mechanical properties and antimicrobial activity of DRCs was systematically investigated.The results show that the prepared ZnO@WMS has uniform particle size,high specific surface area and large pore capacity,and the Zn elements are uniformly distributed in the WMS particles,in addition,the pore channels show a pleated structure with interpenetration,and ZnO@WMS is used as a reinforcing filler to strengthen the bond between the two phases by using the resin matrix penetrating into the pores and forming a micro-mechanical interlocking structure with itself,thus enhancing the mechanical properties of the resin composites.The mechanical properties of the DRCs are enhanced by the micromechanical interlocking structure between the two phases.The test results showed that the overall performance of ZnO@WMS was optimal at 7 wt%loading,with 30.0%,32.3%and 22.0%increase in flexural strength,flexural modulus and compressive strength,respectively,compared with the pure resin without ZnO@WMS,while the inhibition rate of the resin composites against Streptococcus pyogenes reached 84.9%.In addition,the in vitro cell activity test results showed that the DRCs had good cytocompatibility.2.The low filling amounts of ZnO@WMS prepared in the previous chapter resulted in DRCs with high volume shrinkage,which could not meet the requirements of DRCs for clinical applications.In order to further improve the comprehensive performance of the ZnO@WMS-filled high-strength antimicrobial DRCs,this section introduces silane-modified barium glass powder（BGP-M）as the compound filler and investigates the effect of the mixed filler of BGP-M and ZnO@WMS on the various properties of the filled composite resin.The results showed that the polymerization shrinkage of the composite resin filled with BGP-M and ZnO@WMS was significantly reduced;in addition,the surface silanization modification of BGP-M further improved the mechanical properties of the composite resin by forming a chemical bond with the resin matrix and enhancing the interfacial bonding between the two phases.Among them,Z₇B₅₃ composite resin has the best overall performance,and it has certain antibacterial performance against Streptococcus pyogenes（Inhibition rate was 79.4%）.In addition,the Z₇B₅₃ composite resin has significantly improved the barrier performance,which meets the requirements of ISO 4049:2009 standard and is beneficial to the clinical diagnosis of secondary caries.