All ceramic crowns

A full coverage crown is a method of replacing or strengthening the coronal structure of a severely damaged tooth.

It essentially covers the entire part of the tooth that is above the gums. Usually, a grossly decayed tooth can be restored back to its original form and function by placing a crown on top of it.

Include a post endodontic restoration, that is covering the tooth after an RCT has been done. Since, a tooth is hollow after RCT and the coronal tooth structure is only filled with a restorative material, the crown helps to hold the walls of the tooth together so that it can withstand the heavy masticatory or chewing forces.

It can also be used to make aesthetic corrections in a situation where a tooth is severely discoloured, and simple bleaching or laminates are not good enough to achieve the desired results.

Crowns can be made of a variety of materials. Most commonly used ones are the Porcelain fused to metal (PFM) or All Ceramic ones. There are many variations of the all ceramic crowns as well, but we will not be getting into the technicalities for this discussion.
Metal ceramic crowns are made of a metallic substructure, which when unpolished is black in colour with ceramic being fired on top of it to make it look like a tooth. To mask the black colour of the underlying metal, an opaque layer of porcelain is first used, followed by other layers of ceramic for the final contouring and shaping.
This opaque layer makes the prosthesis appear ‘dead’ as it fails to pass any light through it. However, a well made PFM crown is also very realistic and diﬃcult to distinguish from a natural tooth. The major problem with PFM crowns lies with the fact that, all the layering and repeated firing process makes the crowns very prone to ceramic chipping. And once this happens, the unaesthetic black metal gets exposed in the oral environment, which appears pretty obnoxious.
On the other hand, all ceramic crowns being make of a single material are way more resistant to chipping, making them more durable. Also, since these crowns allow light to pass through which makes them look more aesthetic and life like.
Some all ceramic crowns are also layered to make them even more realistic. In the unlikely event that this layered ceramic chips, the advantage of the inner layers also being tooth coloured comes in handy.

Crowns being safe with MRI

Regardless of the material you choose for your crowns, it is very important to note that all crowns are safe with the MRI machine.

The MRI machine uses a magnetic field to create a radiographic image of hard and soft tissues of your body. Please note that any metal used to fabricate crowns essentially are NON – MAGNETIC. Hence, if you have Porcelain Fused to Metal (PFM) crowns in your mouth, rest assured they will not interfere with the MRI machine causing any damage to your body.