Too much pain on a tooth with temporary crown

If the pain has only started after you had the temporary crown fitted, and the tooth is not sensitive to hot or cold, but only to touch, then most likely the temporary crown is a little too big at the back and is being bitten on too heavily by the lower tooth. Get your dentist to polish down the back of the temporary crown to eliminate any contact with the lower teeth.
The other possibility is that the nerve inside the tooth is already dead, and you have an early-stage abscess on the tip of the root, making it painful to touch. In this case a root canal will be needed to save the tooth.

If the tooth is not sensitive to hot or cold, as stated in the original post, then it is unlikely that the pain is coming from something as simple as cement washing out. If the tooth is painful to touch, then the socket in which the tooth sits is inflamed, right at the root tip. The only 2 possible causes in this case are either the temporary crown being too big, affecting the bite and causing trauma to the tooth (interesting that you mention jaw joint pain - this would fit with the crown affecting your bite), OR the tooth nerve has died already, and there is an infection on the tip of the root.
You cannot see a tooth nerve on an X-ray, but you CAN see changes in the density of the bone around the root tip, providing evidence of either bite trauma or a dead nerve. If it's a dead nerve, then root canal and antibiotics are the only solution.

It may take a few days to settle down if the problem was due to the crown being bitten on too much. It's a bit like hitting your thumb with a hammer; you can get rid of the cause, (throw the hammer away) but it still takes several days for your thumb to recover. Your tooth is similar. If the tooth is feeling better by the time your endodontist appointment is due, cancel it. You only need to see the endodontist if there's no improvement after 3-5 days.