A bit of help.

[OneDay111]

I have a tooth at the back, some of you may know.

It's not a wisdom tooth, mine are not out yet. It's the back molar. I have almost a fine cavity across the gumline, under the tooth. I recently had this filled heavily, however abit fell off. I went to the dentist they claimed that it was fine. I'm going for the second time, however I want to avoid the root canal treatment, which was being considered before.

I have heard that root canal causes bad breath. I have booked another appointment and hopefully They can fill it up.

I'm just wondering is this a cavity or something worse, it isnt as super sensetive as I thought. Considering how close it is to the gumline.

Also is smells bad when I shove my tounge into it, not my finger, but only usely near the end of the day.

[halitosisux]

If I were in your position, I'd have the tooth filled normally again. If the BB goes away, as it should if the tooth is responsible, then you know where your BB is coming from and can decide to either leave it with the filling
for as long as your BB doesnt return, or have the tooth extracted.

[OneDay111]

Ok so tooth extraction> root canal.

So I can get an artificial tooth or something like that? Will that be a better option in the absolute worst case scenario, than root canal.

[halitosisux]

Focus on dealing with that cavity for now to see what happens with your BB.
If it works then you and your dentist can decide what to do as a more permanent solution.