A crown, which many patients call a cap, is something that covers the tooth like a helmet.
Crowns are used when a tooth has cracked a piece away or has been filled so many times that there is not a lot of tooth structure left to encase the filling, so something to cover and protect the tooth is needed. Many times we place a crown to keep the tooth from breaking even more, and from breaking into the nerve. It is often better to fix a tooth with a crown before it hurts rather than waiting for the cracks to cause pain as the cracks tend to be very large once they begin to hurt.
At our office we have the technology to make crowns in one visit using a computer called CEREC. With the CEREC we can take a photo of the tooth using a precise laser camera, then with CAD/CAM technology we design the crown while the patient reads or watches a movie, and at the end of the appointment the crown is glued on without having to wear a temporary or take goopy impressions. The crown looks and feels just like a normal tooth!