So, your dentist said you need a crown…and not the princess kind.  Why? What is a crown?
A crown is basically a hat for your tooth.  A crown covers the entire tooth and prevents it from breaking.  A tooth can need a crown for many different reasons.  Basically, anytime a tooth is missing more than half of its tooth structure, it needs a crown.  So, if a tooth is broken, or has a large cavity, or has an old large silver filling it may require a crown.  It is very common for teeth with older silver fillings to need crowns.  Silver fillings are harder than tooth structure.  Therefore, if you have a large silver filling, through normal wear and tear, it will cause the tooth to break down around it.  The tooth will develop crack lines and eventually break.  I will often recommend crowns on teeth with large silver fillings that have crack lines.  If we can restore the tooth before it breaks, it will almost always save the patient time and money.  
Crowns are also used cosmetically.  Almost every smile you see in Hollywood has been altered.  When people come in looking for the Hollywood smile, they often need crowns on their front teeth to create the perfect smile.  Using crowns, teeth can be reshaped, recontoured, and even repositioned to create a more optimal appearance.  
So, if your dentist says you need a crown, smile!   Your dentist is either trying to save your tooth or make it prettier!!!