Hello Debbie, from your symptoms,it seems either your are having acute inflammation of the pulp or something called Crack Tooth syndrome . In case of crack tooth syndrome , nothing is visible in x -rays, very difficult to diagnose ! Only optical fiber trans illumination method can detect it. In this case enamel of tooth has fracture lines, which are not visible in x -rays! For this the only treatment is removal of tooth.Second cause may be pulp damage which could be due to sudden blow to tooth, high heat,etc without the presence of dental caries! It seems the pain is severe,so you can try some anesthetic gel such as Benzocaine gel(Trade name- BENZOCAN ) If it is crack tooth syndrome,there is no use using warmsalt water! Visit another dentist and tell him the details. You can ask me with details, on email. Take care.