The Synthesis And Properties Studies Of Fluorinated Composite Resin With Low Water Sorption

At present,resin composites have been widely used as dental restorative materials for restoring treatment of the tooth decays instead of amalgam alloys,glass ionomer cement and ceramics due to their superior esthetics,adhesive properties and easily operation.However,with the development of filling technology and the expansion of application scope,the performance requirements of the filling resin material are also gradually improved.Ideal filling resin composite,not only has the good physical properties,also need to have good mechanical strength,which can afford enough chewing pressure and friction;Also it need to keep a good chemical stability,so that is not easy to degrade and fracture when using in the oral environment.The traditional resin composite material often leads to the gap formation of the repair material and tooth tissue,teeth edge fracture and even the secondary caries because of the existence of higher polymerization shrinkage.So how to improve the mechanical properties of composite resin to ensure clinical service life,decrease the polymerization shrinkage,and improve the repair edge integrity,it is a key problem to be solved in the application of composite resin.Thus,in order to solve the above problems,this paper is used to design and synthesis a new resin monomer with low polymerization shrinkage and high performance,which can be used as a matrix resin or combine it with Bis-GMA to be used as resin matrix.In addition,we expect that the introduction of inorganic fillers can further enhance the physical and mechanical properties of resin composites,and then it can be used as a kind of new dental restorative materials.The research work of this paper can be divided into the following several parts:First:we use the two-step method to prepare the?4-trifluoromethyl?phenylhydroquinone epoxy?4-TF-PQE?,and using it and acrylic acid to synthesis4-TF-PQEA monomer.The structure of 4-TF-PQE and 4-TF-PQEA are characterized with FTIR and ¹H NMR.Second:The resin formulations consist of Bis-GMA,4-TF-PQEA,TEGDMA,1%of CQ,1%of DMAEMA.Different mass ratios of 4-TF-PQEA/Bis-GMA/TEGDMA are used as matrix resins,such as 0/70/30,10/60/30,20/50/30,30/40/30,50/20/30,60/10/30,70/0/30.According to the dentistry standard,doubled bond degree,polymerization shrinkage,water sorption,water solution,cure depth,mechanical properties,cytotoxicity.etc tests are evaluated.Bis-GMA based resin formulation is used as control.Third:compared to each group of resin formulations,the optimal group is used as the matrix monomer for dental restorative resin composite.Then,the SiO₂nanoparticles and microparticles are used as fillers to enhance the mechanical properties of resins.Moreover,the performance of them are evaluated.We make the following conclusions:The new fluoride resin monomer 4-TF-PQEA is successfully synthesized.According to test results,the monomer containing fluorine resin with low viscosity.After mixing it with Bis-GMA to prepare resin systems,the data shows that only4-TF-PQEA-based resin system has the highest double bond conversion,the lowest polymerization shrinkage and the lowest water absorption and solubility dur to the existence of fluorinated monomers.As the Bis-GMA content in the resin system increases,the above properties are falling.In the mechanical performance test,groups containing Bis-GMA have higher flexural strength and compression strength,and those are gradually increasing along with the increased content of Bis-GMA.In thermal stability results,there are no significant difference among the data groups.In cytotoxicity test,70/0/30?wt%/wt%/wt%?resin system has better cell vitality,each resin system meets the standards.Taken together,the quality ratio of 30/40/30?4-TF-PQEA/Bis-GMA/TEGDMA?system can be used as the best proportion of resin.Second,fluorinated monomer endow the resins with low viscosity,low shrinkage and low water absorption,etc.Using 30/40/30?4-TF-PQEA/Bis-GMA/TEGDMA?system as matrix resin,and prepare the resin composites containing 0 wt%,10 wt%,20 wt%,30 wt%of silica nanoparticles composite resin and 0 wt%,10 wt%,20 wt%,30 wt%and 40 wt%,50wt%silica microparticles successfully.The study found that the introduction of two kinds of inorganic fillers are effectively to improve the mechanical properties of resin systems and reduce the polymerization shrinkage of composites.Besides,the resin composites that contain the same content of filler particles,nano-composites show better mechanical properties.Based on all properties of each groups,we find that the resin composite containing 50 wt%sio₂ micrparticles keeps the best performance in all respects.