Tooth Sensitivity for over 5 Months on New Crown

Hi:The bite has to be checked in all directions to make sure there are no interferences.  Also if you are a clencher or a grinder you need to wear a night guard at night.Best,Dr. Maddahi

It is common to have some sensitivity following the placement of a new crown.  It sounds as though it is somewhat improving, but not completely gone yet.  I would say that you should give it more time.  Your dentist is correct in stating that you could be grinding and the  minor differences in your bite from the new crown could be causing the tooth to stay bruised.  I would consider an occlusal guard that you would wear at night to see if the remaining discomfort subsides.  If it does not,  then perhaps seeing an endodontist for the potential need for a root canal would be a good idea.  Good luck. 

I know that a sensitive tooth can be a real pain to deal with, no pun intended. Getting a crown placed requires a lot of steps that can irritate the tooth...water spray, air spray, sculpting down the tooth....all for a good reason, which is to protect and restore your tooth. These things can irritate the nerve of the tooth and it can take time for sensitivity to subside. 
A dentist can check all of the directions your teeth can slide and hit together. One tiny interference from a sideways motion can cause this sensitivity. Sometimes these interferences are difficult to replicate. If the crown is adjusted and the interference is removed, it can take about 1-2 weeks for the symptoms to fully resolve. 
If it is root surface exposure causing the sensitivity, you can get MI Paste from a dental office which has minerals to help stop your symptoms and protect the tooth.