How Does a Dentist Prepare Teeth for a Crown?

Crown preparation is a routine procedure which should be 100% pain free with properly administered local anesthesia. The dentist simply reduces the tooth in a  circumferential manner  to allow ample room for the crown to be placed. Proper reduction of the tooth will allow for the Crown to be structurally durable while at the same provide a natural feeling to the patient in terms of size and fit. If the Crown is to be made at a Dental Lab the Dentist will fabricate an Acrylic Temporary Crown to keep the patient comfortable until the Permanent Crown is delivered to the patient. This process generally takes about two weeks to complete.

To fit a cap over a tooth you have to allow room for it .

your dentist will reduce the tooth in all directions and check your bite to see that there is enough clearance for the dental technitian to stack the porcelain and or metal/porcelain 

The guidelines are a space of at least 2 to 4 mm around and on top of the tooth ;to carve this space your dentist will make you fully numb and will let you go home with an acrylic temporary crown to protect the tooth

It should not be painful and the dentist should make sure that you are not in any kind of pain during the procedure. Some kind of discomfort is inevitable specially if its a back tooth , a hard to reach area. But again there shouldn't be any pain associated with the tooh. You should be comfortably numb. The first appointment is usually long when the dentist reduces the tooth structure and makes an impression either by packing cords or electro surg/laser/etc. and then a temporary crown . The second appointment, final crown cementation , should be a small one .

Some offices do single visit crowns, whereby the final crown is cemented the same day making the appointment  a little more longer.

There can be some post-op discomfort in the tooth and or around the gums but the dentist should discuss all this with you before starting the procedure.