goodbye tooth

i've had a black tooth, which i presume is dead, for many years which luckily doesn't show unless i smile widely.  about six months ago a big piece of it broke.  no problem as there was no pain and no sharp edges to cause discomfort.  last night i had a maxibon ice cream and one of the little nut pieces felt extremely hard.  it was huge as most of the tooth broke off and there is only one 'crown' left.  it still doesn't hurt or cause discomfort but i suppose it's time i went to the dentist.  i have a very good dentist but he has the most unpleasant receptionist ever.  she's really a nasty person which is unfortunate as i don't want to change dentists but because of her (or maybe i'm just using her as an excuse) i haven't been to see him for ages.  i badly need a clean and now with the broken tooth i think it's time.  i'm wondering if the piece that broke off is actually an old filling.  who knows