When you first leave our office your new crown will feel "like a rock" even if the bite is perfect. This is because anything new in your mouth takes awhile to get used to. This strangeness generally lasts for about 24 hours.
The only way to break porcelain off a new crown is if the bite is off and you chew on it too aggressively. Therefore, plan on not chewing on your new crown for at least 24 hours. If at the end of that time you have not bumped into it or scraped against it and it is feeling normal in your mouth then, and only then, can you start lightly chewing on it. If, on the other hand, the bite still feels strange then you must wait another 24 hours before chewing on it. If you can't get used to the crown after three days you will need to contact us for a bite adjustment appointment. DO NOT WAIT! If you do, one of three bad things can happen: either you will break off porcelain or the tooth will get sore or you will get used to a crown which is not fitting perfectly. This is analogous to having a pebble in your shoe and not removing it. Your gait would be off but it would be so slight that you wouldn't notice till your ankle or knee or hip started to hurt.
Expect a little cold sensitivity for a few days. In fitting and cementing the crown the tooth is exposed to air for about 30 minutes and, in addition, the bonding procedure is a little obnoxious to the nerve of the tooth. It will often take a few days for the nerve to calm down. Occasionally a crown will take much longer to settle down. This is because the nerve of the tooth must not have been in perfect shape. As long as the sensitivity is slowly improving there is nothing to worry about.
Do not floss for 24 hours to give the cement a chance to cure. You can start brushing right away.
Expect a little gum sensitivity because you were not able to floss while the temporary was on and also because we had to "poke" around while cleaning up the cement. This should improve rapidly. After the first night you can rinse with a little warm salt water to hurry the process along.
It's a good idea to avoid extremes in temperature the first day.