Dentists please read, previous root canal crown got taken off...?!

I went to the dentist this morning to get my crown re cemented bc it was getting loose. But the dentist found the crown had gone bad, so he removed it. (very painful). I thought he was going to put a new crown back on it, but he gave me gaws and sent me on my way. I asked why he wasnt replacing it today and he said the gum has to heal. So my question is....


How long after getting the crown taken completely off, can I get a new crown?