Why is my root-filled tooth sensitive?

[SixImpossible]

Last year I had a root canal filling in a premolar. The tooth had been giving me problems on-and-off ever since the old filling in it had come loose. The loose filling had caused me terrible pain, and was quickly replaced. That happened 2-3y ago.

Last year the tooth started getting sensitive again, and the dentist decided to do a RCT. Afterwards I had no pain or sensitivity.

But now, 6m or so later, I'm beginning to have unpleasant sensitivity in a tooth that I thought has no nerve.

What's happening?

Could be that they didn't get all the tissue out when they did the root canal. This seems to happen a lot with RC treatment!

But surely then I'd have been in pain after the RTC?

It's my third, and neither of the others has ever given me any trouble since they were done (apart from the crown fillings falling to pieces after 20y).

The RCT, I mean.

They can be settled for years but if there's still a bit of living tissue then eventually bacteria can get in and cause an infection. Sometimes having the root canal redone helps but the success rate falls each time it's done.

Antibiotics?

The aim of the root canal treatment is to remove a damaged nerve and bacteria from the root canal space. If this is not achieved or bacteria get in again the infection is then trying to spread through the roots into the bone surrounding the tooth. The body usually defends itself and keeps bacteria under control. This often is chronic condition and largely asymptomatic. However every now and then the active balance between the bacteria in the root and the defence systems of the body shifts and the bacteria become stronger. On these occasions the symptoms may vary from mild discomfort to significant pain and swelling. The tooth can be little sensitive or very tender to pressure or even slightest touch. Antibiotics will restore the balance but will not remove the bacteria inside of the tooth, as there is no blood supply in the root canal space to deliver the antibiotics. Only root canal retreatment can help to resolve the condition in the long term.

I had this in one of my root canals. The dentist just did a repair and it was fine. She didn't need to go down very deep, the repair was quite superficial, but the fault was enough to allow temperature changes in the tooth which caused some pain and sensitivity. Luckily, no infection had got in.

It was diagnosed with a simple x-ray.

Thanks for the explanation. Is it the sort of thing that is better dealt with immediately? Or should I wait and see whether it gets worse? No pain as such, just sensitivity to tapping and to temperature changes.

Oops. NCFail. I'm the OP.

I had rct on a tooth in 2009, last year an X-ray show the tooth had an infection at the bottom. Didn't get round to going back and we have a new dentist, she removed it last week and took an X-ray today. There is nothing left and the infection is finally gone. I refused to have rct again as the tooth had been troublesome for 10 years.