Missed MB2 canal as per this CBCT image, or neuropathy, to explain continued pain after root canal treatment?

[ToothPatient]

The large canal, MB1. He got this, cleaned it fully.

The more difficult to discern canal, MB2. He got the access to this (3 or 4 mm in) as in the image, it's easy to see (frontal plane, bottom left).

But said he couldn't get any farther in.

.......

Endo said he thinks neuropathy is a more likely explanation, but I've read so much about missed MB2 canals and continued symptoms and infection, seems more likely to me.

........

Basically, does that second image portray or convey an actual canal that could be MB2?

And it's not just a short access (3 or 4 mm the endo said) and nothing more?

 

[Dr M]

It looks like there might be a MB2 present. More than fifty percent of molars have an MB2. If you are unhappy with the explanation of the endodontist, perhaps get a second opinion from another endodontist. Any MB2 that was not cleaned out properly, could lead to recurrent infection and become symptomatic

 

[ToothPatient]

It looks like there might be a MB2 present. More than fifty percent of molars have an MB2. If you are unhappy with the explanation of the endodontist, perhaps get a second opinion from another endodontist. Any MB2 that was not cleaned out properly, could lead to recurrent infection and become symptomatic

The issue in this case is I'm still experiencing pain signals.

Not that a recurrent infection could occur later, but that right now there's still nerve like pain coming from the tooth.

Endo said he thinks this could be some kind of neuropathy (but he also said that although he identified an access, he can't really get into that MB2 canal).

But based on that scan, it seems evident enough to me an MB2 canal is likely present, which presumably if not cleaned out, could be causing those pain signals I'm still dealing with post RCT.

I'm just trying to get clarity on whether that CBCT scan does illustrate the MB2 canal?

 

[Dr M]

There is a MB2 on the CBCT. The pain you are experiencing currently is most likely due to this canal. I would not jump to the conclusion of neuropathy, until all other options or causes have been investigated.

 

[ToothPatient]

There is a MB2 on the CBCT. The pain you are experiencing currently is most likely due to this canal. I would not jump to the conclusion of neuropathy, until all other options or causes have been investigated.

One thing that worries me is a possible bone infection.

I experienced an abscess prior to the RCT during which time the pain was insane and I couldn't even touch the tooth.

That has cleared up, but there's still residual pain, not dissimilar to what I had prior to the RCT, maybe slightly less intense as the bulk of the nerve has been removed, but it's still there.

Bone infection frightens me cause of resorption and other issues cascading from that.

After the RCT I also stayed on anti-biotics for five days, with no additional reduction in pain or symptoms.

.........

How would I know if I had a bone infection?
Would the pain be very intense, similar to the abscess like pain?

 

[MattKW]

1. I don't agree that an MB2 is visible based on those low-res images you are showing; I'd want to see better pics.
2. Do you have xrays taken after the root filling was completed?
3. You are having "nerve-like pain" (hot/cold/sharp sensitivity?). That suggests a live tooth, but you said this tooth had been abscessed. So that doesn't make sense. I'd be looking at other teeth too. Strangely, you say the residual pain is "not dissimilar" to what you had before.
4. There are many MB2s missed or so calcified that full instrumentation is not possible, yet the vast majority of upper 1st molar endos are successful. It is impossible to completely eradicate all bacteria from an abscessed tooth (lateral canals, isthmuses) but because they are so reduced in number, the body can tolerate the residual.
5. Reinfection is more likely to feel like a dull ache, with the tooth tender to percussion.

 

[ToothPatient]

1. I don't agree that an MB2 is visible based on those low-res images you are showing; I'd want to see better pics.
2. Do you have xrays taken after the root filling was completed?
3. You are having "nerve-like pain" (hot/cold/sharp sensitivity?). That suggests a live tooth, but you said this tooth had been abscessed. So that doesn't make sense. I'd be looking at other teeth too. Strangely, you say the residual pain is "not dissimilar" to what you had before.
4. There are many MB2s missed or so calcified that full instrumentation is not possible, yet the vast majority of upper 1st molar endos are successful. It is impossible to completely eradicate all bacteria from an abscessed tooth (lateral canals, isthmuses) but because they are so reduced in number, the body can tolerate the residual.
5. Reinfection is more likely to feel like a dull ache, with the tooth tender to percussion.

Would you be open to me e-mailing you my CBCT scan for a closer inspection? (same to Dr M?)

The second image above:

You don't think this is an MB2 canal?

Screen shot from the CBCT, I just adjusted the contrast and resolution (to high precision) to highlight the canal.

 

[ToothPatient]

X-rays after completion, and pics below also:

MB2 canal orifice (smaller, but I understand that's not unusual:

 

[ToothPatient]

1. You are having "nerve-like pain" (hot/cold/sharp sensitivity?). That suggests a live tooth, but you said this tooth had been abscessed. So that doesn't make sense. I'd be looking at other teeth too. Strangely, you say the residual pain is "not dissimilar" to what you had before.

Endo mentioned this could be possible neuralgia, like residual nerve sensation as it has been left painful for so long, that the connecting nerve continues to transmit pain signals? (this has eased marginally as of the last day or two, thank heavens)

There's not temperature sensitivity, minimal palpation sensitivity (a good hard tap with finger elicits mild discomfort, not pain).

Pain comes exclusively from the root area of this tooth, no other teeth.

1. There are many MB2s missed or so calcified that full instrumentation is not possible, yet the vast majority of upper 1st molar endos are successful. It is impossible to completely eradicate all bacteria from an abscessed tooth (lateral canals, isthmuses) but because they are so reduced in number, the body can tolerate the residual.

Of course I don't understand endodontistry well enough to comment on this, but the endo could only get 3 or 4 mm in.

I had attributed this to possibly:

2:30 for where the endo explains that "troughing" the canal is necessary to access it?

Now, re what you've mentioned, naturally I don't know if it's a case as per the video, where the correct angle wasn't attained to access the canal, or it's been as you say, "calcified"?

Bearing in mind the tooth abscessed on the 22nd of November, and was root canaled on the 28th of November, but had been painful for about 4 months prior to that (deep filling).

1. Reinfection is more likely to feel like a dull ache, with the tooth tender to percussion.

This feels/is more like shooting nerve pain.

But you don't think residual nerve would be responsible for that?

 

[ToothPatient]

And two more of a file in the MB1 canal:

 

[MattKW]

Those Xrays don't show the finished RCT, only the working length measurements. Have you actually had the RCT filled with gutta-percha, and do you have xrays of the finished treatment taken from at least 2 different angles (or a CBCT)?

 

[ToothPatient]

Those Xrays don't show the finished RCT, only the working length measurements. Have you actually had the RCT filled with gutta-percha, and do you have xrays of the finished treatment taken from at least 2 different angles (or a CBCT)?

It's not finished.

First stage only (three canals cleaned, mb2 uncleaned).

There's a temporary filling on it at the moment.

Endo does the first stage then assesses for entire pain and infection resolution before filling the canals.

At present, there's still pain.

 

[MattKW]

Do you know what material they have placed in the canals as an interim dressing?
Often it is CaOH (calcium hydroxide) as it is a potent disinfectant due to high pH (alkalinity). However, it also rarely causes considerable post-op pain.
In such rare cases, I drop back to a corticosteroid paste like Ledermix and see what happens. Maybe ring and ask your endo about this.
My wife has had 3 RCTs and reacted painfully each time to CaOH - the first 2 were simple RCTs that I did myself so it was easy to swap to Ledermix, and then obturate a week later. The 3rd tooth was a wisdom tooth that I sent to an excellent endodontist. The same problem arose and when I rang him he was not eager to change to Ledermix - well, that's easy for him to say! It's not his wife in pain! So I swapped it to Led, and sent her back to him for obturation ( I told him what I did!), and it was finished successfully.

 

[ToothPatient]

Went to another endo.

Apparently he had to use something called a "hypersonic" as the mb2 was "buried deep", but according to him there was a fourth canal.

Some inflammation after the treatment was painful.

One week and one day on, it's improvement but there's still an ache.

No idea what to do now, give it more time I guess, see if the ache fully resolves.

 

[ToothPatient]

Is it possible the endo could have missed a part of the MB2 canal?

I have no reason to ask that apart from skepticism and on the CT scan above, it should the MB2 outline looks like it contours the root, so perhaps a portion of it could be missed?

He said the first portion was "calcified", then he reached a point where a hand file could clean the remained of the canal (said it was "buried").