Study On The Preparation Of Multifunctional Mesoporous Silicon-based Microspheres And For The Improvement The Properties Of Dental Resins

Dental resin composites have gradually replaced traditional silver amalgam and become the first choice for clinical patients and doctors to repair defective teeth,due to their strong operability,good physical and chemical properties and excellent aesthetic properties.However,the clinical data show that service life of the resin composites is limited and stress fracture and secondary caries are the two main reasons for the failure of the prosthesis.Although the performance of the resin composites can be improved by adjusting the morphology of inorganic fillers or adding antibacterial functional components,the presenting modified materials have a single function,and the mechanical strength of the composite resin is often reduced when the antibacterial property is improved,which can not meet the needs of long-term service in complex oral environment.Therefore,the construction of multifunctional fillers to simultaneously improve the mechanical properties and antibacterial property of dental resin composites,has become a critical issue in the field of dental composite resin research.Based on the unique microstructure of mesoporous materials and excellent load/slow-release performance,in this paper,we proposed to construct mesoporous silicon-based multifunctional fillers to enhance the performance of dental resins.The antibacterial propertiy of resin composites was endowed by loading antibacterial active components,,and the interface bonding strength was improved by micro-nano scale interlocking between the resin matrix and fillers to prepare dental resin composites with excellent comprehensive performance.The specific researches are as follows:Zinc doped mesoporous silica nanoparticles(Zn-MSNs)were prepared by a sol-gel method,and the effect of Zn-MSNs on the mechanical and antibacterial properties of the resin composites was studied.The results showed that theprepared Zn-MSNs have good dispersibility,uniform size and even-distribution of Zn.Mesoporous fillers were well dispersed in the resin matrix.When the amount of Zn-MSNs was less than 15 wt.%,the mechanical and antibacterial properties of the resin composites gradually increased with the increase of the amount of Zn-MSNs.The resin composites with 15 wt.% Zn-MSNs showed the best comprehensive performance,the flexural strength,flexural modulus,compressive strength and micro-hardness were 31.21%,50.47%,53.83% and26.79% higher than the neat resin,respectively and the antibacterial rate reached99.99%.In addition,in vitro cytotoxicity tests showed that the incorporation of Zn had no obvious side effects.On the basis of the previous chapter,mesoporous bioglass microspheres(MBGs)with excellent biological activity and mineralization promoting function were prepared by a sol-gel method,and their applications in the modification of dental resin composites were studied.The results showed that the prepared MBGs have excellent dispersion,uniform size and good mineralizing property.The mechanical properties of resin composites were firstly increased and then decreased with the increase of the contents of MBGs.The flexural strength,flexural modulus,compressive strength and micro-hardness of the resin composites with a filler content of 30 wt.%increased by 44.2%,62.5%,36.46% and 27.55% compared with neat resin,respectively.The biocompatibility of the resin composites was significantly improved.When 8 wt.% Chlorhexidine acetate(CHX)was loaded into MBGs(CHX-MBGs),the antibacterial rate of resin composites with 30 wt.%CHX-MBGs reached 100%.The mechanical strength of the composites was lower than the samples with MBGs,but it was still significantly higher than that of neat resin.