UV Synthesis Cross-Linked Poly Methyl Methacrylate Particles For Resin Denture Teeth And Composite Resin

Recently,photocuring technology attracted a great deal of attention due to its many obvious advantages.PMMA and its derivatives are known for their medical applications,particularly for hard tissue repair,resin denture teeth and regeneration.The aim of this study was to investigate the feasibility of UV systhesis cross-linked polymethyl methacrylate particles for resin denture teeth and visible light-curing composite resin.Firstly,With the initiator concentration increasing,the PMMA particles size increased;the molecule weight of PMMA particles increased then decreased.With the monomer content increasing,the particles size increased;the molecule weight of PMMA particles increased gradually then decreased.With the ratio of water and ethanol decreasing,the PMMA particles size decreased;the molecule weight of PMMA particles increased gradually.With the time of irradiation increasing,the molecule weight of PMMA particles decreased gradually.Secondly,these cross-linked PMMA particles were used for preparing the resin denture teeth.The polymethyl methacrylate(PMMA) particles have unreacted double bond,which can react with methyl methacrylate (MMA) monomer during polymerization,it may increase the wear resistance of the resin denture teeth.When the concentration of cross-linking agent increased from 1wt%to 7wt%,the sizes of particles decreased;the density of particles decreased from 1.058 to 0.8508 g/mL; the glass transition temperature of particles decreased from 127.5℃to 100.1℃gradually;the Brinell-hardness of resin denture teeth decreased from 21.2HB to 14.6HB gradually;the value of water sorption increased from 5.97μg/mm~3 to 39.71μg/mm~3;the value of solubility increased from 0.98μg/mm~3 to 4.89μg/mm~3;the storage modulus of all materials were around 10~9MPa,as the temperature changed from 0℃to 37℃;the value of abrasive wear decreased from 38.34 mm~3 to 24.90 mm~3.Thirdly,these dried cross-linked PMMA particles was used for preparing composite resin.The polymethyl methacrylate(PMMA) particles have unreacted double bond,which can react with monomer resin during polymerization,it may increase the adhensive between organic fillers with basic resin.When the concentration of cross-linking agent increased from 1wt%to 10wt%,the sizes of particles decreased from 2μm to 500nm;the density of particles decreased from 1.293 to 1.015g/mL;the glass transition temperature of particles increased from 132.3 to 137.5℃gradually;the Micro-hardness of composite resin were around 20HV;the value of water sorption decreased from 8.21 to 7.69μg/mm~3;the value of solubility decreased from 0.48 to 0.08μg/mm~3, then increased 0.25μg/mm~3;the light curing depths of composite resin were around 3mm;the flexural strength of composite resin were around 90MPa;the storage modulus of all materials were around 10~9MPa,as the temperature changed from 0℃to 37℃;the shrinkage of composite resin decreased from 3.70 to 3.50%,then increase to 3.60%;the value of abrasive wear decreased from 29.13 to 25.25mm~3,then increased to 30.30mm~3.These results indicated that the synthesized cross-linked PMMA could satisfy for the requirements from mechanical properties point of view.