Grinding a tooth before getting a crown may be mildly painful. If a root canal has been done the grinding is generally not painful. Crowns may require the patient’s tooth to be ground down, and generally the extent of the grinding is not large, so there is basically no significant pain symptoms, but everyone has a different degree of sensitivity, so the sensation of the emergence of the same, some people may have a slight pain. If you have had a complete root canal, the grinding itself will not cause any pain. Crowns may generally be required at the end of the root canal treatment. The main purpose of wearing a crown is to protect the tooth so that it does not lead to an increase in brittleness and symptoms of tooth damage later in life. It is usually a good idea to polish the tooth before the crown is placed so that it fits the crown better. Crown restoration process usually pay more attention to protect the teeth, avoid excessive chewing.