Whats the difference between a regular cap or crown, and these metal-free restorations?
The difference is like night and day. The technologies are completely different. The method of their fabrication is completely different. First of all, traditional metal or porcelain-metal caps or crowns have all-metal undersides. This technology began in the early 1900’s. Cements have to be used to fill the space between the metal and the tooth. The porcelain is placed over the metal to hide the dark metal. This is very difficult to do well, and many porcelain-metal crowns still look fake no matter how well they are made. And metal or gold crowns look like gold crowns. The metal free restorations are usually prepared as inlays, onlays, and sometimes as crowns when needed. Inlays and onlays are much more conservative. Secondly, the metal-free components are made of all-ceramic, composite polymers, or fiber reinforced polymer. These are then fused, or bonded to the natural part of the teeth with resin cements that polymerize and seal the space between the restoration and the tooth. This
