Here is some advice if you have broken a tooth or filling or both. Firstly, does it hurt or is it just a bit rough or sharp. If it is painless do not worry, there is no urgency but it will need attention. If it is a bit sharp then rub the sharp edge with an emery board to smooth the edge a bit. If it is only sensitive to hot,cold and sweet things the sensitivity should ease a bit but it indicates the tooth is alive and yes you need to get it fixed. The urgency depends on just how sensitive it is.

If it is developing a continuous dull ache with sensitivity to hot in particular then it needs more urgent attention. See the pain section on toothache of the website.