Any thing artificial you put anywhere has got a certain life! Dentistry is not an exception, where you use it daily ! It requires adequate maintenance from you and your dentist both to have a predictable outcome ! Hope that helps For single crown emax is beat material available! Gold cap lasts ages! I have personally seen 40 years in service!

All the materials used in dentistry are biocompatible material. Basically you have 1. Chrome-Cobalt (Stainless steel coloured) Cap, 2. PFM (Porcelain fused to metal, where you have a metal core with a ceramic layered on it), 3. DMLS crown where it is a PFM crown but CAD CAM machine is used to design the crown and finally you have 4.Metal free, (Zirconia, Disilicate) which also is made using a CAD CAM machine but it completely made of white coloured material without the metal component. There are other materials but do not want to confuse you. Strength wise- All of them can bear the compressive and tensile forces of the oral cavity. (Metal free have higher compressive strength) Aesthetic wise- Definitely Metal free crowns are superior There are reports that as they don't contain metal they do not transmitt temperature changes to the tooth. Fit wise- CAD CAM crowns have better fit and design for a harmonious relation between the adjacent tooth as well. So Metal free crowns are the superior ones in normal circumstances.

There are various types of caps available today right from full metal to Pfm ( ceramics fused to metal) or all ceramic. Pfm has variants like cad, dmls etc. All ceramics have variants like emax or zirconia. Each has its own indication depending on the tooth and the case.

Metal free crowns are definitely better. Over the years lot of individuals are developing allergies to the metal.

All ceramic crowns are always the best

Hloo Sir . You can get zirconia crown they have guarantee And if you are Spending money  you can get it replaced by the lab But maintaince of crown and oral hygiene are all in hands You have to take care of that You can also practoconsult us Regards

Metal free cap(which is Known as zirconia) are better than the caps you get with metal inside and the ceramic outside,"zirconia" has a much more higher strength than the metal ceramics,it prevents the black margins which appears  near the gums in a period of time with those metal ceramics.