Most people have or will eventually hear the words  ”you need a crown for this broken tooth “while visiting their dentist. This may seem to be bad news at first because the procedure is usually more time consuming than a routine filling and also may require a second visit to deliver  the crown.  Another major concern will be the cost which is always greater than that for  a simple filling. The flip side to all of this is that the tooth can be saved. With today’s technologies a human tooth has to be decayed almost beneath the level of the bone to be condemned to the extraction forceps.  Nobody wants to lose a tooth if they don’t have to and dental crowns are used every day to fix damaged teeth.
Many patients will ask why a crown is recommended rather than a filling. The answer lies with the degree of damage present. A general rule of thumb is that if fifty percent or more of the tooth’s circumference is compromised a crown may be recommended. This, of course  is always a judgment call made by the dentist. Unlike a filling , which serves only to occupy the space damaged by decay inside a tooth, a crown fits completely over the tooth right down to the gum line all around. A filling gets it’s strength from and is held in place by the tooth whereas a crown actually affords  new strength to  the compromised tooth.  Crowns are made to mimic the size and shape of the original tooth so that the row of teeth that it exists in remains stable and so that all chewing ability is restored.
What  materials may a dental crown be  constructed from?  From a functional standpoint arguably the best material a patient can ask for is 18 carat gold. This is because a gold crown is literally impossible to break which is a huge factor when restoring a back chewing tooth that is subjected to large forces. Another factor which has made gold popular is that it wears away at a rate very similar to natural teeth so that a person’s bite will remain balanced for the life of the crown. Unfortunately gold has lost it’s popularity for most people because of it’s appearance. Many patients ask for dental work that looks like the original teeth and will not allow even the smallest filling to be made from anything except tooth colored material. A large gold crown is usually out of the question due to esthetics. For decades porcelain fused to gold crowns have been very popular because they are strong and they are tooth colored. A metal coping that is much like a sewing thimble is cast to fit intimately on the prepared tooth and  is then covered with baked on ceramic. Both porcelain-metal and full gold crowns are hand crafted in specially equipped laboratories by technicians that are mindful not only of function but of appearance as well. These highly trained individuals are artists in the true sense of the word.
Newest on the list of available crowns are cad-cam generated prosthetics. This amazing technology allows for the production of the crown while the patient waits thus eliminating the need for the patient to return for the delivery. For standard porcelain or gold crowns to be made a three dimensional  impression must be taken in order for a model or replica of the broken tooth and the surrounding teeth to be made. This means that the patient must sit still for at least three minutes with an unappetizing goo which gradually hardens up in their mouth. Not so for the newer technique. Instead of an impression tray a small streamlined camera is used to take a “picture” which is really an electronic three dimensional rendering which is then viewed on a flat screen through a computer program. The crown is then “made” on the screen using tools provided in the program and when properly sized the information is wirelessly transmitted to a milling chamber where the final crown is produced from a solid block of porcelain. After any necessary adjustments are made the crown is glazed or polished and permanently cemented in place.