Why is there no pain after my crown fell off?

Just because you have a crown, doesn't mean that the tooth has to be sensitive, especially if the preparation of the tooth for the crown was conservative, and did not approach the pulp. Each tooth has different anatomy. Also, the pulp responds differently based on the number of times the tooth has been treated, and/or the amount of trauma it has received. I suggest you see a dental professional, and DO NOT attempt to "re-glue" the crowns yourself.As with all information, ask your local dental professional prior to any decisions/treatment.Hope that helps!

It is not unusual to have no sensitivity in a tooth that has had a crown on it for some times if that crown falls off.  It does not mean it will need a root canal treatment though it is a possibility.  It is best if you see a dentist as soon as you can to have an evaluation done and a treatment plan made.  Don't delay as the teeth could easily decay.  Good luck!