An Experimental Study On The Influences Of Resin Matrix And Curing Systems On Mechanical Properties Of Resin Composite

[Objectives] By researching the influences of three kinds of resin matrix on physical and chemical properties of resin composites, the optimal ratio of resin matrix for a new type of resin composites was investigated. By studying influences of the curing agents of chemical curing system and light curing system on properties of resin composites, the optimal plan of double curing system of resin composites was discovered and a base for a new whisker/nanoparticle reinforced dental resin composites has been formed.[Materials and Methods] The experiment consisted of three procedures. First, three kinds of resin matrix:Bis-GMA, UDMA and TEGDMA was mixed in different proportions. Adding light curing agent and making standard specimens, the flexural strength and the elastic modulus of specimens on a computer-controlled Universal Testing Machine to investigate the optimal ratio of resin matrix were tested. Second, different ratio of the initiator BPO and the accelerator DHET were added to the optimal ratio team and standard specimens were made. Certain chemical curing system was made by flexural properties experiment, gelatin experiment and FTIR. Third, different ratios of the photosensitizer CQ and the amine activator DMAEMA were added into the optimal ratio team and the standard specimens was made. Certain light curing system was made by flexural properties experiment and FTIR.[Results] 1．The flexural strength and the elastic modulus of resin specimens, which consisted of different ratios of resin matrix, had significant differences. When the mole fraction of TEGDMA:Bis-GMA:UDMA was 50:0:50, the flexural properties was optimal (the flexural strength was 71．02 MPa and the elastic modulus was 1．81 GPa). 2．BPO/DHET-chemical curing-initiating system had significant differences to the flexural strength and the elastic modulus of resin(P<0．05) . When the mass proportion of BPO was 0．8% and DHET was 0．4%, mechanics properties (The flexural strength was 87．78 MPa and the elastic modulus was 2．91 GPa) and technic indexes(The monomer conversion was 80．19% and the gelatin time was 5 minutes)were optimal.3．CQ/DMAEMA-light curing-initiating system had significant differences to the flexural strength and elastic modulus of resin (P<0．05) .When mass proportion of CQ was 0．3% and DMAEMA was 0．1%, physical and chemical properties was optimal (The flexural strength was 75．06 MPa and the elastic modulus was 2．78 GPa. The monomer conversion was 75．45%.).[Conclusions] 1．Resin matrix has significant effects on the mechanics properties of resin composites .The different proportions of three kinds of resin matrix have effects on the flexural properties of resin composites. 2．When mole ratio of TEGDMA:Bis-GMA:UDMA was 50:0:50, the mechanical properties are optimal. 3．The concentrations of BPO and DHET have effects on the flexural strength and the elastic modulus. 4．In BPO/DHET-chemical curing-initiating system, the optimal mass proportion of BPO is 0．8% and DHET is 0．4%. 5．The concentrations of CQ and DMAEMA have effects on the flexural strength and the elastic modulus of resin. 6．In CQ/DMAEMA-light curing-initiating system, the optimal mass proportion of CQ is 0．3% and DMAEMA is 0．1%.