The Preparation And Characterization Of Dental Composite Resins With Nano Zirconia And Porous Fluorphlogopite/fluorapatite Filler

Objective:To prepare compound fillers by mixing nano zirconia powder and porous fluorphlogopite/fluorapatite powder with different proportions. Composite resins were prepared using the compound fillers. To analyze the effects of different contents and different components fillers on the characterization and conversion rate of the self-made composite resins and provide theoretical basis of developing an excellent new composite resin.Method:nano zirconia powder and porous fluorphlogopite/fluorapatite powders were prepared by chemical precipitation method and melting method with two-step heat treatment respectively. Then compound fillers were prepared by mixing two kinds of powders with different proportions. Light curing composite resin were prepared using the compound fillers and resin matrix by the method of vacuum premixed infiltration. The resins were divided into A60group, A65group, A70-1group, A70-2group, A70-3group, A70-4group and A75group according to different contents and components of the filler. P60 composite resin used in clinic were selected as control group. The characterization and structure of the filler and composite resins were studied by using scanning electron microscope(SEM)、transmission electron microscope(TEM)、X-ray diffraction(XRD)、intelligent automatic Raman spectrometer、atomic force microscopy(AFM) and specific surface area and pore size analyzer. Furthermore, the C=C double bond conversion rates of the composite resins were measured by using intelligent automatic Raman spectroscopy. SPSS19.0software was used for statistical analysis.Results:1. The distribution of the nano zirconia powder prepared by chemical precipitation method was uniform and dispersive. The size of the powders were about20nm and crystal phase was monoclinic phase. The specific surface area of Fluorphlogopite/fluorapatite powder prepared by melting method with two-step heat treatment was27.12m2/g and there were a lot of three-dimensional interconnected pores after acid etching by hydrofluoric acid.2. The SEM、TEM、AFM showed that:the fillers distributed uniform and dispersive in composite resins using nano zirconia powder and porous fluorphlogopite/fluorapatite glass ceramic powder as fillers. The matrix surrounded the surface of the fillers or scattered in filling powders. There were nano filler particles and resin matrix in three-dimensional pores.3. The conversion rates of A60group, A65group, A70-1group, A70-2group, A70-3group, A70-4group, A75group, P60group were60.68%、71.41%、79.71%、85.38%,60.35%、52.79%、52.33%、80.24%respectively. The differences of composite resin conversion rate among groups were statistically significance (P<0.05).Conclusion:1. Using chemical precipitation can prepare a uniform particle size distribution and good dispersibility monoclinic phase nano zirconia powder.2. Using melting method with two-step heat treatment can prepare porous fluorphlogopite/fluorapatite glass ceramic powder with three-dimensional connected pores.3. The fillers distributed uniform and dispersive in composite resins using nano zirconia powder and porous fluorphlogopite/fluorapatite glass ceramic powder as fillers. There were good combinations between matrix and hybrid fillers4. With the increasing of inorganic fillers mass ratio in the resin,the conversion rate was firstly increased and then decreased. 5、With the reducing of nano zirconia powder content, the conversion rates were firstly increased and then decreased in the same content groups.