Why (or-is) putting crowns on teeth which almost require root canal, is no longer done?

[babyag]

Hello,
I would like to ask about a technique that was practiced in the past and why was it dismissed in the present.

Once upon a time (20 years ago) it was popular (at least in my country) that in borderline cases where the tooth is almost in a need of a root canal (the pulp was not infected, yet, but a filling was unfeasible for some reason) the dentist would glue a crown on the tooth and leave it as such. Usually it would hold for 10-20 years before the tooth would actually require a root canal.

Nowadays my dentist says that this technique is obsolete and in borderline cases you just perform a root canal (his reasoning on the matter was "Because that's what we do now").

If someone could explain as to why is it so it would be be truly a tremendous help.

Thank you very much!

 

[MattKW]

If molar teeth start cracking cusps, there comes a point where more fillings won't have anything to hold onto. Personally, I draw the line at 2 broken cusps. Then, it is recommended to do a crown while there is still some natural tooth to encircle. If you wait for all the cusps to fracture, then a crown is of doubtful usefulness. Which is similar to what you are saying for "borderline cases". This hasn't change. All procedures cause damage to the tooth, so although a crown can physically strengthen the tooth, it also causes damage to the nerve and in ~10% of cases the nerve will die. Now you have to do an RCT through the crown - a pain in many ways, and patients don't always understand this risk.
Unfortunately i have heard of some dentists who simply do the RCT before a crown. There are various reasons you could speculate as to why, but one might be that it avoids the risk of post-op crown pain, and an RCT for a patient who doesn't like a hole drilled through their crown.

 

[honestdoc]

Dr. MattKW is correct. There are so many dental opinions...some may be more motivated with money. On "borderline cases" that need a crown, I would prep and place a well-made temporary crown. I would monitor the tooth for about 3 months. If a root canal procedure is needed, I will access it through the temp crown and complete as appropriate. If the tooth is good, it will feel cold of mild to moderate intensity at short duration. The tooth may need a root canal after the crown is cemented. It may be more difficult to access through the final crown and locate all the root canal anatomy. I would recommend a more experienced dentist or specialist to perform that procedure.

 

[Busybee]

This seems entirely dependent on the dentist. For the second time I am in a position where two dentists disagree on whether to do a root treatment. It's incredibly frustrating. In both cases there was no evidence of root infection on x ray but what one dentist sees another seems to imagine. Particularly the case when x rays are of poor quality.

 

[MattKW]

This seems entirely dependent on the dentist. For the second time I am in a position where two dentists disagree on whether to do a root treatment. It's incredibly frustrating. In both cases there was no evidence of root infection on x ray but what one dentist sees another seems to imagine. Particularly the case when x rays are of poor quality.

Normally an Xray is the last decision about whether a tooth needs an RCT. You can't always tell if the tooth is dead and abscessed from an Xray. It's usually the other signs and symptoms, like tenderness to tapping, no sensitivity to cold stimuli, and history of the pain, that determine the need for an RCT. The most important need for an Xray for dead teeth is to see the root shape so as to determine the likely difficulty of an RCT.

 

[Busybee]

Here they always use x ray and symptoms to make a decision. The reason I didn't have rct on second opinion on the other tooth years ago is because the x ray showed no indication and I had cold sensitivity. That tooth is still sound (just a new filling fixed it). The dentist who referred me this time did not test for cold sensitivity and made a decision based on his interpretation of the x ray and the fact that I'd been having twinges along with the fact that the tooth had a lot of decay removed (not my fault btw but a leaky crown nobody had wanted to touch). . The second opinion said wait a couple more months. The tooth still has cold sensitivity. The pain seems down to either the way the temp was done or the build up. Either way it's subsided since the second opinion took a bit of height off the cusp.

Having an rct when a tooth might settle without one seems a no brainer to me. Yes it's a risk not to but surely once a tooth is filled there is always a risk it could die with re treatment. There is also always a chance it will be stable for decades. The outlay is possibly another crown.

 

[MattKW]

Here they always use x ray and symptoms to make a decision. The reason I didn't have rct on second opinion on the other tooth years ago is because the x ray showed no indication and I had cold sensitivity. That tooth is still sound (just a new filling fixed it). The dentist who referred me this time did not test for cold sensitivity and made a decision based on his interpretation of the x ray and the fact that I'd been having twinges along with the fact that the tooth had a lot of decay removed ...

Sensitivity to cold indicates the nerve is still alive, and may recover (reversible pulpitis), for which an RCT is not indicated. Pain to hot stimuli indicate the nerve is dying (irreversible) pulpitis, and an RCT is likely. In neither of these cases will there be any signs on an X-ray. I'm simply saying that an X-ray is not the first step in assessing whether a tooth needs an RCT or not; it is usually the last step.

 

[honestdoc]

The reason why x-rays may not be fully diagnostic is that they are 2 dimensional. Many times there may be disease on root that does not show on the x-ray. That is because the outer bony plate is still intact. Like Dr. MattKW mentioned, there needs to have many steps in assessing the problem. There may be other factors that can mimic tooth pain such as sinus pain.

 

[Busybee]

So putting the x ray aside, if a tooth still feels the cold and doesn't have pain on hot would you root canal it just because it's been having twinges like toothache?

 

[honestdoc]

I would not do the root canal. There is potential for the nerve to settle down like Dr. MattKW mentioned. If the pain is worsening and one cannot tolerate it, it may be the sign of the nerve becoming irreversibly damaged and a root canal may be indicated. I tell patients if the tooth is waking them up at night and or having swelling, the tooth may need a root canal.

If the x-ray looks suspicious (bony plate has been penetrated or has bony defect) but the patient has all the signs of the tooth being VITAL such as No Pain, cold test sensitive of normal intensity and duration, negative to percussion & palpation, no mobility and perio WNL then this is a rare case of Cemento-osseous dysplasia which is a benign condition with normal pulp and teeth. Root canal treatment is not indicated. That is why many steps such as those mentioned above are critical in assessing the need for a root canal.

 

[Busybee]

Matt and Honestdoc that is exactly what the second dentist said. Thanks for confirming. I may well need a root treatment but I'm going to wait another two months and see what happens.

 

[honestdoc]

If you have cold sensitivity, avoid colds (easier said than done). The pulp is inflammed and if you can minimize it you have a better chance the nerve can settle down. You may not need a root canal. I had a tooth on Upper Left #13 that had significant pain. I was grinding and clenching and traumatized it. I was afraid to chew on it. Fortunately it settled. Find a more conservative dentist not motivated by production or money.