Dr. Brian Saby's Dental Blog

If you were to take a survey of the “over 40” crowd.  You would find that the majority of people over 40 have had numerous fillings in their teeth, especially the back teeth.  You would also find that most of the old fillings are silver amalgam and likely quite large. (Feel free to try this at your next summer barbeque; it will make you the topic of conversation for months.)

The prevalence of dental restoration in that demographic group is largely due to the fact that this group missed some important dental developments during their formative years.  Fluoridation, dental sealants and the importance of flossing and brushing in the pre-teen years being the main advances in protection against tooth decay that were advanced shortly after this age group got their first cavities.

Fortunately, dentists have been very successful in the treatment of dental decay.  For many years now we have been proficient in placing fillings teeth that have been affected by decay.   Unfortunately, fillings have a limited life span and fail over time.  Each time a filling fails the next filling needs to be bigger.  At a certain point, there may be too much filling and not enough tooth to produce a good result.

Dental fillings were designed to fill a hole in the tooth using the remaining tooth to support the filling.  When the filling exceeds a certain size the remaining tooth structure is too brittle to hold the filling without fracturing under the strain of chewing.  This results in fracture of the remaining tooth.  To prevent tooth fracture or to repair a tooth that has fractured the dentist will recommend that the tooth have a crown.

A crown (also called a cap) is a restoration that covers the outside of the tooth.  The crown acts to hold the tooth together and replace the missing tooth material.  Think of it as a casing for the tooth.

To produce a crown, a thin veneer of tooth material is milled from the outside and the top of the tooth.  This produces enough space for the restorative material and allows for the crown to be shaped so it can function like a tooth.  Usually, 1 to 1.5 mm of tooth is removed around the tooth and 1 to 2mm removed from the biting surface.  A very accurate rubber-like impression is taken of the tooth and a plaster model is produced that is exactly like the prepared tooth.  A dental lab technician will then construct the crown that fits the model, and therefore the tooth precisely.  The crown is then cemented over the tooth preparation, any you are on your way to years of happy chewing.

Crowns can be made of a number of materials.  The most conservative, longest lasting material is still gold.  The malleable nature of gold allows for final finishing in the mouth that makes for best seal.  The main drawback of the gold crown is the colour. 

If esthetics is a concern, a veneer of porcelain can be made over the gold of a crown.  With modern, porcelain technology, these teeth can be made to be indistinguishable from natural teeth.  New technology even allows for all porcelain crowns that fit well, are strong and have the maximum esthetic potential.  This is especially helpful when the tooth to be crowned is near the front of the mouth.

Dr. Saby can help you decide if it is best for you to have crowns on some of your teeth and if so, what type you should have.