I have Sensitive Teeth

I have a sensitive teeth and I've been complaining about this painful sensation every time i drink or eat something extremely cold and hot.
Just like last time when my mom bought us an ice cream. I just can't eat it because my teeth is reacting so fast and it's really painful. Actually even when i drink a cold water, sometimes, i have to take a straw to sip it just to avoid that painful teeth reaction.
The only way to keep myself away from that painful reaction is by using this special toothpaste made just for sensitive teeth. Right now, I'm using this Colgate Pro-Active which is quite expensive compare to the normal brands, (And i think Colgate should commend me for promoting them in this blog LOL)
Anyway, it is really effective though the result will not last for long and i have to brush my teeth again after it loses the effect.
Even though i prevent that painful reaction through this special tooth paste, i still need to consult a dentist and maybe he can provide a permanent solution for it.
I'm just hoping that i can find a service similar to that Dentist Portland, I'm sure they can do something for my sensitive teeth in no time.