Tapering should be visible but not exaggerated but still evident. This means that once you check for the taper it is visibly evident that there is a taper on the walls. One way of checking is to place a perio probe along the walls and also you may check for any undercuts as well.
ERRORS
The only reason for coming up with this error is that the operator failed to make the bur parallel to the long axis of the tooth. Remember that the bur has its own taper which is just enough to make your walls with the right taper. Just that you have to maintain your bur parallel to the long axis of the tooth and that’s it.
PREVENTION
Before starting any crown prep, always check for the long axis of the tooth. This will dictate the line of draw of your crown and the angle of your bur as well. Take note that the angle of the bur is very important when doing a lower molar tooth because of its unique lingual tilt.
