Procedures

Crowns

Procedure overview

Alternate terms: Caps.

In dental terms, the clinical crown of a tooth is that portion which is covered with tooth enamel and projects through the gums into the mouth (i.e. the part you can see, as compared to the root).

If a tooth has been extensively decayed, chipped or cracked, and cannot be restored to its proper form, function and esthetics another way, the dentist may recommend placement of a prosthetic crown. However, the descriptive term "prosthetic" is generally implied by the context, and not stated (e.g. "Mrs. Jones, your tooth needs a crown" implies the tooth needs a prosthetic crown). Crowns are most often made in a laboratory by a dental technician, and the process is very labor intensive.

Crowns for primary teeth differ significantly from crowns for permanent teeth, from the process of preparing the teeth to the fabrication of the crowns and treatment options. For more information, see Children's oral health › Crowns for primary teeth.

In February 2008, the American Dental Association reported that, in an effort to reduce costs, some dental laboratories have begun having crowns made in China, and that some of those crowns have been found to contain lead, a metal which is toxic to humans. The extent of the problem is not currently known. Reputable dental laboratories generally furnish an alloy certificate with each crown, declaring the composition of metals used to fabricate the restoration. If you have doubts, ask your dentist for a copy of the alloy certificate.

Post-operative discomfort

A common misconception about teeth is that working on them, like trimming fingernails, should not lead to any complications. In reality, though, working on teeth is a surgical procedure. Teeth are very well-supplied with two different types of nerve tissue. And unlike other tissues of the body that are living, teeth can't swell, and are poorly equipped to deal with inflammation. Working on teeth very commonly produces inflammation—just as making an incision in an arm or leg would. Inflammation is a process by which your body sends immune cells and healing cells to the affected area so that they can repair the "wound". It does so by increasing blood flow to the affected region.

When the surgery is performed on soft tissue (i.e. skin, muscle), increased blood flow to the area produces swelling—enlargement of the soft tissues—which are somewhat elastic (i.e. "stretchy"). Since teeth cannot swell, inflammation causes the blood pressure inside the tooth to increase. The increased pressure on the nerves inside may produce significant discomfort. Well-maintained dental instrumentation, skilled technique, and use of desensitizing medications can minimize post-operative discomfort, but may not eliminate it.
Learn more: Diagnoses › Irreversible pulpitis
Learn more: Diagnoses › Reversible pulpitis

Anything that causes a pressure change inside an inflamed tooth can provoke more discomfort. The most common culprits are cold temperatures and chewing. Cold causes the fluid inside the tooth to contract (shrink), changing the pressure. Chewing sends small hydraulic compression waves through the extra fluid in the tooth, and these pulses are perceived as pain. Sensitivity to heat is a symptom in some cases, but generally heat sensitivity is less common. Severe sensitivity to heat is a sign that there may be gas in the tooth. This is an unfavorable situation, because the gas is usually produced by bacteria (i.e. the tooth is infected). Sometimes the only way to reduce the pressure in the tooth is to make a hole into the pulp space (i.e. perform a root canal).
Learn more: Diagnoses › Acute apical abscess

Some people are inclined to think something must have been done wrong if they experience discomfort after a dental procedure. Although this can be the case, if proper procedure is followed, it is more likely the tooth's reaction to what was done that causes the problem. Does this mean you should wait until your tooth hurts to fix a problem that has been diagnosed? Definitely not! Very often problems with teeth (i.e. cavities, etc.) don't hurt unless they are advanced. Waiting until the problem is advanced to fix it is a big mistake. The bigger the problem is, the harder it is to fix and the more likely it is to produce complications; and it will frequently have a poorer prognosis (likelihood of long-term success) if you wait too long to have a problem fixed.

If your dentist can show you the problem (e.g. on the X-ray, with a photo, etc.) in such a way that you have a clear understanding of what it is, how it can be fixed, with how much urgency it should be addressed, any options you may have for fixing it, the risks, and intended benefits of each, the likelihood of success ("prognosis") of each, and the cost of each, you will experience better treatment outcomes.