how long had you had it? If you didn't knock it loose by eating crunchy apples or anything then maybe the rest of the tooth itself was what worked loose? As rowan suggests, I'd be getting a dentist to look at it in case of infection.
Unfortunately you need to get the "hole" seen to see if there are any more nasties. Unfortunately hole will close and you could be in for an infection.
I have had a hole in my crown since a week after it was put in 7 years ago!!! I ended up with a massive infection and despite root canal etc everytime they closed it up I got an infection!
well just rinse your mouth constantly with luke warm and salt and concentrate on that area of the broken tooth. do this many times and of course spit. good luck - dont talk to me about teeth - could write a best seller.
I would have thought the hole now left behind, with the nerves exposed, would probably cause you some pain sooner or later.
I don't envy you. I too hate dentists :-(
Aw Helen, I feel for you..... at least if there is no tooth at all left, nothing else is going to happen, but it's worth having it checked to make sure it HAS all gone. Was it root-canaled before the crown?