| Porcelain-Fused-to-Metal Restoration is also called Metal-Ceramic Restoration, in which the intensity of porcelain crown and bridge are strengthened by fusing porcelain to the metal, and the prosthesis are not only good in strength but also pleasing to the eye. Metal base or frame is classified into many kinds according to the different forming technique and different alloy, and there are many choices in clinic. But normal metal restorations such as cobalt alloy base or nickel alloy base are too hard in strength, bad in marginal adaptation, and apt to appear gingival black line. Especially the biology compatibility of some component of normal alloys are questionable and had absorbed more attention, and in some developed countries, some normal alloy are limited in using or even banned in use. In our country these years several kinds of porcelain fused noble metal restorations are used in clinic, and the effects are good in short term as same as long term. With the rapid economic developing of china, porcelain fused to noble metal restoration will become the main trends of metal -porcelain restoration.To Metal-Ceramic Restoration, good metal ceramic combination is the key to the success of Porcelain-Fused-to-Metal Restoration. The new high noble PFM metal materials- AGC galvano-ceramic prosthesis System and Heraeus AURA System were selected in this study. Diffusing and distributing of elements in metal-ceramic combinational area were observed by EPMA-electron probe micro-analyses, appearance characters of metal-ceramic combinational area were observed by EMS, combinational strength of metal-ceramic combinational area was measured, so that to analyze the role of gold bonder in AGC electroforming frame and ceramiccombination . The metal-ceramic combinational interfacial area of Heraeusnoble alloy after reused was also studied as a subsequence of Heraeus noble alloy reusing research). Results:1 In the metal-ceramic combinational area of galvano-ceramic prosthesis, galvano base and porcelain combined closely to each other , no bubble be find; There are ionic diffusing and microelement content change in the interfacial area; good mechanic telescoping be observed in interface. 2 In the study of action analysis of AGC gold bonder in galvano base and porcelain combination, when compared with the not used gold bonder group, there is no new elements be fond in used gold bonder group and there is no obvious element diffusion trend outlook change in the used gold bonder group; But the width of ionic diffusion is obviously increased in used gold bonder group. Electron microscope result show: in the interfacial area of the not used gold bonder group, a few bubbles can be observed. In the interfacial area of used gold bonder group, there is no bubble; because the sample number of shear bonding strength test is limited, no statistical difference is fond in shear bonding strength between two groups.3 In the porcelain fused to reused Heraeus noble alloy interface study, the result is that: in new Heraeus BHN gold alloy and porcelain combination interfacial area, metal and porcelain is tightly combined, no crack, few bubbles, and the bubble diameter is about 3-5 urn, Zn has peak value in interfacial area, and after the reusing of alloy Zn content decreased in interface, in the group being added one third of new alloy in the metal-ceramic interfacial area with the reused time added bubble number added, the group of simply recast was found bubble number and bubble diameter are all increased obviously, the biggest bubble diameter about 20um ,and there is obvious crack.Conclusion:1 There is microelement diffusing in interface of metal-ceramic combinational area of galvano-ceramic prosthesis ,it means there is chemical bond; galvanic base and porcelain combined closely to each other, no bubble, it has mechanical bond, compressive bond and Fandehua force .physical and chemical combinations are two main combination way of porcelain and galvanic base..2 In the interfacial area of galvanic base and... |
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