A Comparative Study On Five Frequently Used Alloys Bond To Porcelain

Porcelain-fused-to-metal crown is a compounded body made up of metal and porcelain, and it has the merit of both the metal crown and the porcelain crown: high strength, withstanding rub, without ageing, lower heat conducting, better biological consistent, good color and shape effect to nature teeth. At the same time, the manufacture method that porcelain fused to metal avoided the defect facet porcelain crown's crisp and easy been broken off. The basic require of a good made porcelain-fused-to-metal crown is that the porcelain layer can't be peel away from the metal surface when it bear all directions of stress that chew function gave. One of the most important cause of the failure of porcelain-fused-to-metal restore is that the porcelain layer been peel away from the metal surface because of the low bonding strength. So, to invent the metal or alloys that has more higher bonding strength and manufacture methods that can achieve higher bonding strength are the same aim of lots of scholar have try to achieve from its born. Because different metal or alloy has different self bending strength, there are same difficult to compare different kinds of metal's or alloy's bonding to porcelain strength, so ,there are only very seldom report on thistheme both the civil and the offshore journal. This study is trying to compare five kinds of frequently used in porcelain-fused-to-metal restoration metal's and alloys' bonding strength. Materials and Methods1. Materials Ni-Cr alloy Ti alloy Pure Ti metal 75.6%Au alloy 89.5% Au alloy2. Methods(1) The manufacture of metal samples:0.3mm thick wax specimen was fabricated into 40mm><3mmx0.3mmshape,caste to get metal samples.(2) Metal sample prepared before cover porcelain: every metal sample be prepared with frequently used methods in clinical.(3) Cover porcelain on metal samples: Every metal samples were covered with porcelain in the middle 10mm, the thickness of the porcelain layer is homogeneous lmm, the area of the porcelain is 10mm 3mm(4) The testing of the bonding strength: A three-point bending test was used to survey the bonding strength of every sample.(5) Data analysis: The data were analyzed with a one-way analysis of variance.Results( 1 ) Ni-Cr alloy has the same bonding strength with Ti alloy PureTi metal 75.6%Au alloy, but has a lower bonding strengththan 89.5% Au alloy. (2) Ti alloy has the same bonding strength with Pure Ti metal 75.6%Au alloy, but has a lower bonding strength than 89.5%Au alloy.(3) Pure Ti metal has a lower bonding strength than 75.6%Au alloy and 89.5% Au alloy.(4) 75.6%Au alloy has the same bonding strength with 89.5% Au alloy.Conclusion:( 1) 89.5% Au alloy has a especially high porcelain bondingstrength than the other four group . (2) Pure Ti metal used to porcelain-fused-to-metal crown shouldimprove its bond to porcelain strength.