Also, moutwashes should be avoided on a daily basis. Most of them contain Alcohol. Alcohol destroys all bacteria (bad AND good!) also, alcohol can cause a dry mouth. Dry mouth = insufficient saliva which can result in tooth caries and decay.
Mouthwashes make your breath feel fresh - they can also cause mouth ulcers. Avoid as much as possible.
OK firstly, is the pain triggered by hot or cold?
It may be your wisdom teeth (as you say it's near the back)
Is it painful to bite on?
Sensitivity is usually triggered by cold air or cold drinks or sweet foods. The cause is usually receeding gums.
Do you have any cavities?
My guess is that it is your wisdom teeth. They may be erupting soon.. or maybe be partically erupted which means that they are erupting through the gum.
marnagelman - If the pain is trggered by Cold - it's sensitivity. If it's triggered by hot, it could be your tooth dying.
Sensitivity can be treated by applying Sensodyne (sensitive toothpaste) to the sensitive area. Keep the toothpaste in your pocket so it is always kept at body temperature. Apply it throughout the day like you would cream.
I have the same symptoms! It is so strange because I have been able to identify the tooth with my dentist and the xrays are clear. There are no cavities on this particular tooth, which is on the upper right side of my mouth.
I am concerned I may need a root canal to get the pain to stop, but I don't konw what is wrong and I can't take the pain.
I noticed that I almost prefer the pain of cold water to the pain I get in the tooth.
Well, from my own personal experience of a lifetime of sensitive teeth due to very poor enamel, sensitivity IS generally a flash of "pain sensation" flowing through the tooth, rather than an extended ache. I do know that on a couple of occasions when I needed root canals, the endodontists did pain tests and told me that one indicator of the need for a root canal is extended pain, brought on by sensitivity factors but lasting much longer than the usual quicker jabs of pain. Sounds like something more is going on deep within your effected teeth than basic sensitivity. Exposed nerves from lack of enamel coverage causes sensitivity; it's the nerve reacting at THAT MOMENT. If the pain doesn't ease up when the stimulant is removed, something else is going on deep within the nerve that is not simply sensitivity.