Why does a Toothache come and go?!

Why does a Toothache come and go?

I have a toothache that comes and goes. I believe it's the tooth right behind my k-9 (or fang) tooth. Sometimes it hurts SO badly I have to take perscription vicoden because ibprofen, aleve, tylenol-nothing else works. It's been that way for two days and, because of the holiday I can't see my dentist until Wed. When it hurts it is a CONSTANT SHARP but dull pain. Eating and drininkg do not intensify it. And the only thing that helps is a wet tea bag held there the entire time. Anyhow, my question is.....why does a tooth ache come and go? At this moment it is not hurting at ALL, it feels completly normal, but in 15 min I could be ready to bang my head aginst a wall because it hurst so badly. I'm just curious :-) Thanks so much in advance!!
God Bless!

It sounds like an infection in the tooth to me. Normally when over the counter meds. do not relieve the pain it is more advanced infection, and that will require antibiotics. Your tooth has a nerve in it that is attached to your circulatory system. With the beat of your heart, blood is being pumped into the tooth. The nerve is inflammed, therefore it is swollen and it is hitting the walls of the inner chamber we call the canals of the tooth. If the infection can not "leak" out then it is trapped and pounding to get released. Normally, I've found that toothaches especially hurt, like ear aches will during the night time. The blood rushes easier to your head when you are lying down. More rushing equals more pounding. The tea bag confuses me somewhat because, that is what I normally recommend for bleeding gums. It has tannic acid in it which, is used to toughen up skin (tanning hides). Since the tea bag relieves the pain, your problem could be related to a gum infection, which can hurt like a tooth infection. You will need your teeth cleaned very thoroughly if this is the case.