What is a crown? What is a cap?
Crown and cap refer to the same restoration – material that protects the entire coronal or crown portion of the tooth. They come in many different types and hybrids of material – all porcelain/zirconia (tooth color), all-metal (various alloys and/or gold), porcelain-fused-to-metal (part porcelain and part metal).
When is a crown needed?
A crown may be needed for a number of conditions.
- Cracked tooth. Much like a cast is placed on a broken arm to protect it, in this case, a crown holds the tooth together to prevent the crack from radiating. If the crack radiates down the root, the tooth may need to be removed.
- Cavity that is too big to be filled. This can occur due to a large decay or a previous filling that has started to break down or damage over time.
- Multiple surfaces with fillings. Imagine a leaky roof that has been patched up over the years as defects arise (e.g. decay, crack, chip, broken margins, etc.). Over the years, the leaks are patched until it reaches a point where the patching material makes up more than the original roof. At this point, replacing the roof is recommended to prevent the patch materials (fillings) from collapsing and destroying the house (tooth) on one rainy day (eating, grinding, clenching, etc.). In situations where the remaining healthy tooth structure is inadequate, a crown may be indicated to protect the tooth against the stresses of everyday use.
- Broken cusps. If the damage involves load-bearing anatomy of the tooth such as the cusp, a crown may be necessary to withstand the forces from normal use.
- Root canal treated tooth. This is evaluated case-by-case as not all root canal treated teeth needs crowns.
- Acid erosion. Repeated exposure to acid or chronically low oral pH can cause a rapid loss of enamel leading to exposed dentin. Unprotected dentin is more susceptible to decay and further destruction. Some factors that lead to erosion of teeth include GERD or severe acid reflux and dry mouth. With full coverage crowns, teeth are protected from further damage from the acidic oral environment.
- Loss of vertical height. Severe grinding can cause one to lose vertical height over time. It can be exacerbated with acid erosion. This can cause one’s face to appear shorter and older. Loss of vertical can alter how your teeth come together and lead to joint issues (TMD) over time. To restore loss in vertical height, a full mouth restoration may be necessary.
What does getting a crown involve?
Depending on why you’re getting the crown affects what is done during the procedure. In the presence of decay or fracture, depending the amount of healthy tooth structure that remains, a buildup may be necessary to retain the crown. Once the tooth is prepared, an impression is made. This gets sent to the laboratory to fabricate the final crown. During this time, you will have a temporary crown in your mouth until we see you again in two weeks or less to deliver your final restoration.
When do I need a buildup before a crown?
In situations where there isn’t enough healthy tooth structure to support a crown, a buildup may be necessary to retain the crown. Much like a scaffold that serves as the foundation for a structure, a buildup is a foundation to which a crown is placed.
In the case of a severely compromised tooth, additional treatments may be necessary to hold the buildup. In some cases, restoring the tooth may not be the best option. Dr. Lin will evaluate your unique situation and explain any alternative options as necessary.