When I inform people that they need a crown due to their
tooth cracking I usually get the same response.
How long will it last if I don't get the crown.
The answer to that is usually the same.
Your tooth is cracking because of the pressure being placed upon it during chewing.
Therefore, if you went on an all liquid diet ( thus no longer chewing )
your tooth will last for a long time.
However, if you like to eat nuts, carrots, or anything else that is a
little hard then your tooth could fracture tonight.
There is no way to tell.
If all depends on how you use your teeth.
Cracks will not heal themselves.
They will continue to progress as you use the teeth to chew.
The eventual result will be a fracture.