After preparing all four axial walls of the crown preparation, look through the occlusal view and you can notice that the crown has a rather boxy shape. When viewed occlusally, a crown prep should have a round shape (no sharp corners). Finishing deals with removing any sharp angles around the preparation, smoothing the sharp demarcation (if there are any) on the labial surface between the 2 planes. You can use any bur that you want.

You may want to use a perio probe to check the taper of the walls. Place it close, touching the entire length of the wall. If there is a gap somewhere between the instrument and the wall, it means that the wall is uneven or has an undercut. Remove this by carefully gliding through, sweeping the entire wall in one direction that covers at least 1.5mm.

You may refine the margins from irregularities and roughness. When working on the shoulder margin though, be careful not to get rid of the rounded internal line angle and make it acute. So only apply the hand instrument to the outer side of the shoulder. You may use an end cutting bur, but do not focus it on using on that irregular portion only because you may end up gouging that area instead. Do glide the bur in in wide sections instead, as if sweeping the bumps away.

Upper Canine Crown Preparation Finishing