The Study Of Consistency Of Color Between Porcelain-repairing Resin Composite And Veneering Porcelain

The porcelain-fused-to-metal crown (PFM) have the quality of enough intension like metal and the ideal appearances like porcelain. Because of its stable color,glazed surface, good endurence of abrasion and torsion et al, PFM is popular in dentistry.However there are also many problems.Because of the poor shear strength,faulty process and some man-made factors,which can result in fracture.To the crown which have beening cemented,one of the simple way is to repair it by resin-composite directly. This method has several advantages, including quick application,minimal expense,and simplicity. Nevertheless,these repairs tend to have several shortcomings,such as instable,poor wear resistense and aesthetic appearance problems.With the improvement of materials and techniques, the advent of new systems related to bonding to fractured porcelain make it possible. There have been several studies about the bonding strength between resin composite and porcelain or metal,but few studies about the consistency of color between two of them. In this study,Vita VMK95 dentin porcelain(A2), Ceramco 3 dentin porcelain(A2) and Ceram·X duo nano ceramic restorative resin composite (D2)were chosed. The color parameters L*,a*,b* and translucency(T) values of these materials with different thickness were measured with a spectroradiometer (PR-650),and the color different valuesΔE* were calculated to discuss the consistency of color between porcelain-repairing resin composite and veneering porcelain.The result showed:(1) In different thickness, the color parameters L*,a*,b* values had statistic differences between veneering porcelain and porcelain-repairing resin composite,and the values decreased with the thickness decreased.(2) In different thickness, theΔE* between the veneering porcelain and porcelain-repairing resin composite had no statistic differences,and all the values reached the recognizable ranges by naked eyes.TheΔE* values were in the ranges of clinic acceptability in 1.0mm and 0.8mm thickness.(3) In different thickness,the translucency(T) values had statistic differences between veneering porcelain and porcelain-repairing resin composite,and the values were increased exponentially or logarithmicly with the thickness decreased.In conclusion,this study analysed the consistency of color between porcelain-repairing resin composite and veneering porcelain and there were obvious differences in color between two of them.The color of resin composite should be improved to match the color of veneering porcelain.On the other hand, the study results showed the basic information on the difference in optical properties between porcelain-repairing resin composite and veneering porcelain,it laid a foundation for clinic application of porcelain-repairing.The results also laid a experimental foundation for further studies including several color tabs and materials in different background,cement agent, color combinations and clinic application.