Sudden extreme sensitivity in front tooth!

[ItsAllGonePeteT0ng]

I'm having a rubbish time with my teeth this year.
Just had a root canal done and literally the day before my appointment I started getting a really sharp sensitivity like pain in my front tooth and the one next to it when I was wearing my retainer that night. Ended up having to take the retainer out as the pain wouldn't stop.
Saw the dentist the next day for my root canal and mentioned it and she xrayed it and checked it over and said it was all fine. There is a small filling in it but she said it was all fine.

But something is really wrong!

Smiling and opening my mouth causes the really severe sensitivity. Breathing through my mouth or drinking even room temperature water sets it off.
Sometimes I can't even press my thumb to the bottom of the tooth as that causes the same pain.

The dentist painted something on the tooth and sealed it with the UV which hasn't had any effect at all.

I brush with sensodyne and have started rubbing some on the tooth but that's not having any effect either.

What on earth is going on??
I'm half wondering if it's some kind of sinus infection or something as my nose is permanently stuffy and I feel the sensitivity going right up to my nose.

Its stressing me out as I dread having to eat or drink now.

Anyone else experienced something like this before?

Hopeful bump.

Do you have any food trapped under the gum? Sorry, that's about the only thing I can think of, or grinding your teeth at night? I hope you manage to get to the bottom of it. But yes, go back to the dentist, you can't go on with that sort of pain.

@Tegridyfarms I don't think so as I floss daily so unless something has gotten so deep under there that the floss can't reach it, I don't think it could be that.

I've just brushed and flossed my teeth and the pain started again just from having my mouth open and teeth exposed. It was so sharp that I've covered the two teeth in orajel just to get some relief from it.

I will mention it to the dentist again but am not hopeful she will do anything as it's NHS and she has already said she doesn't know what the problem is so next steps are usually to go private which I have no hope of affording.

I'm really quite stressed about it as I don't want to be stuck with this pain forever.

Have you been eating much citrus? I get sensitivity when I eat citrus.

@dudsville No citrus. Only been eating soft foods for a while as other tooth was so sore both before and after root canal.

I've always had mild sensitivity to cold on most teeth but nothing like this.

It just came on all of a sudden and hasn't gone away. It's a bit extreme to not even be able to open your mouth to brush your teeth without getting bad sensitivity pain!

I don't know what could have happened to trigger it.