A crown is essentially a fixed (cemented or bonded) protective covering for a tooth. Often, a tooth can suffer severe damage which weakens or changes its normal shape.
A crown can be made of several hard durable materials (such as Gold, Porcelain, or Composite Acrylic) that are compatible with the human body.
Crowns are fixed prosthetics carefully crafted to mimic the natural look, feel, and function of a natural tooth before it is fixed and sealed into position over a carefully smoothed and sterilized tooth foundation.
Today, with the rapid rise in popularity of dental implants, a crown can constructed in the same fashion over the implant foundation eliminating the need for a bridge or partial denture.
A bridge is a combination of two or more crowns that are fused together. In a space where a natural tooth has been lost, it is possible to replace the space with a false tooth (or PONTIC) that is supported by the crowns on adjacent teeth.
The bearing weight of a persons bite can approach 300 lbs per square inch, so it is important to assure the strength and health of the adjacent teeth to accommodate the weight load of the pontic*. With the popularity of dental implants, bridges have become much less popular.
An implant with a crown eliminates the need to crown adjacent teeth simply to support its neighbor. Bridges are also a liability to clean thoroughly due to the trapping of bacteria under the pontic.
*Pontic: a false tooth supported by a crown fixed to another tooth. A pontic is always fused to another tooth, and mimics the function and look of a natural tooth. A potic is an integral part of a fixed bridge.