Stainless steel or chrome steel crowns are one of the most durable restorative (filling) material used in pediatric dentistry. They are usually made of stainless steel and hence the name. They are biocompatible and do not corrode in the moist atmosphere of the oral cavity even after many years.

When do you need stainless steel crowns?

Stainless steel crowns are indicated for the following conditions:

• Tooth decay involving more than two surfaces of a tooth (where the normal filling materials do not stay)

• Tooth treated with root canal treatment etc.,

• Sometimes these crowns are used as space maintainers

• Other developmental problems in which the form of the tooth is affected badly

What are the chances for a child to swallow the crown? 
Normally the crown is verified for its tight fit and then bonded tightly to the tooth with a cement. Hence the chances for the crown to be dislodged is remote.
 

Will a crowned milk tooth fall off normally or do we have to remove it after some time?

The crowned tooth is as good as a natural tooth and usually fall of normally
 
Do stainless steel crowns have any advantage over the conventional filling materials?  

Definitely yes, they are the best restorative materials whenever there is extensive decay affecting a single tooth.
 

Is the tooth preparation painful for a child? 

No the procedure is not painful for a child. The tooth preparation is minimal and even if it causes some amount of sensitivity the pediatric dentist can anesthetize the area and carry out the procedure.