Crowns may be removed in one piece but this is rarely the case unless the existing crown does not fit well or if there is significant decay in the tooth structure underneath the crown that has undermined the fit. Most of the time, the method used to remove crowns involves sectioning the crown and removing the segments separately. This minimizes the chances of the underlying tooth breaking.
Non precious metal crowns are made of very hard metal alloys. These crowns can be removed with special metal-cutting burs but due to the nature of the metal alloy, sectioning can take some time to complete.
The key to successfully removing a crown is patience and good magnification. Many dentists use magnifying loupes for precision when working. Magnification reduces the chances of inadvertently drilling into the tooth underneath the crown. Since your crown has a metal layer, this improves visibility by providing good contrast between the crown material and your tooth.
On average, removal of a single crown takes between 10-20 minutes.
And since the crown removal is done under local anaesthetic, it is a virtually painless experience.
Hope this helps!
