Dental Q - Root canal and root amputation

[Laurence Stein DDS]

Hi sbbi,

I went back to the original post in 2004 to bring myself up to speed. My responses that seemed so lucid at the time are even confusing me. Part of the problem is that the actual procedure the patient underwent was unclear.

At times references were made to root amputations, hemisections and retrograde fillings. They are all different procedures. It is also equally difficult to quickly describe each procedure... especially so a lay person can understand it.

You may be confused for the same reason that I find the old post confusing. In your question to me, I think your reference to a hole is referring to the socket hole left behind after a root is removed. On the other hand, the hole I am referring to is the one left behind when the tooth was sectioned and the pulp chamber was opened up as a result.... this is a hole in the tooth.

The socket "hole" will fill in by normal healing. Any hole or other perforation into the pulp chamber must be closed by the dentist. He will usually be doing the post and core followed by a cap or a permanent filling into the pulp chamber.

For a retrograde filling, the holes would be the ones created into the skin and bone to access the root end of the tooth and the hole created by the filling preparation in the end of the root. The hole through the skin and bone will close during normal healing and the hole in the root end must be filled with the retrograde filling.

Let me try to describe, more clearly, the different procedures listed in the original post. Perhaps it will make things easier to understand.

Soooo.... let's try again.

A HEMISECTION is a procedure in which a tooth with multiple roots are made separate by making a cut through the existing crown and all the way through to the supporting bone. The separate tooth sections are treated as if each is a separate tooth or if one of the separated tooth sections cannot be saved, then only that section is extracted and the remaining section is restored. Hemisection WITHOUT the removal of a separated section is often done to improve the restorative prognosis of a tooth with gum disease between the roots or in the event there is a fracture between the roots of a multi-rooted tooth.

The hemisection and subsequent removal of a root from a multi-rooted tooth is called a ROOT AMPUTATION. The hemisection cut may be vertical, horizontal or diagonal. It is often used as a "bail out" procedure to salvage an existing crown or bridge

Since the cut to separate the tooth passes through the nerve chamber in the middle of the tooth, a root canal procedure must be performed prior to the split. If there is an existing root canal in the hemisected tooth, then all that is needed to seal the opening that communicates with the nerve chamber. This can done using a cap or a filling. The technique used will vary from case to case.

A RETROGRADE filling is a filling that is placed into the root end (apex) of a tooth. It is typically used when a traditional root canal procedure cannot be used or when a traditional root can procedure is not successful and the tooth cannot be treated in a convention manner again.

Hopefully, I've managed to answer your question as confusing as all this seems to be.

The photos left to right:
Retrograde filling, hemisected molar, hemisected molar under a bridge with one root amputated.

Regards,

 

[sbbi]

Hi Dr. Stein,

Thank you so much for taking time explaining in details.

Will root amputation create a gap at the top of the tooth where it meets the gum?

Also, what kind of precaution/unusual maintenance that I can take to help the tooth last longer after the root amputation?

My endodontist wants to do this for me.. but I feel a periodontist should do this, so I got a consultation from a periodontist who told me it is most likely the root got cracked. (It is possible due to the "aggressive" root canal retreatment I received from my endodontist, but he could not tell). The periodontist also said it is possible the root is not cracked. In that case, I will need to go back to the endodontist.. This is what happened. Pls find the x-ray photos I attached (it is tooth #3), and pls let me know if you have any opinions.

Thank you so much!
sbbi

 

[Laurence Stein DDS]

Yes, the removal of a root alters the shape of the tooth at the gum. This will alter the appearance of the completed restoration. The good news is that the tooth in question is not very visible and most people won't know anything has been done. If it poses a cosmetic problem, then other restorative options can be explored.

Teeth with root canals are brittle. Stay away from hard foods like hard nuts, ice, hard candies. They can all break the tooth.

The "aggressive" root canal therapy probably refers to the diameter of the finished root canals. They are wider than usual and this means that there is less tooth structure within the roots to support the overlying crown. The tooth should have a core place if there is not one already. I would be somewhat leery about a post within one of the canals. This takes away even more root diameter and may further weaken the remaining root.

Either the periodontist or the endodontist can perform the surgery. You might want to consider placing a bone graft into the resulting socket to preserve more of your own bone in the event you need to extract the tooth in the future and place an implant. The periodontist is more likely to have socket graft material available

An implant would have been my first choice in this case because it is most predictable. That said, the root amputation may well suffice for a number of years.

Finally, have either specialist check the tooth immediately in front of your molar. From the radiographs you enclosed, it appears that something is going on under the hazy, smaller filling in that tooth... could be decay.

 

[sbbi]

Hi Dr. Stein,

Thanks again!! I am concerned about the "gap" at the top of the tooth where it meets the gum, more because I think the food debris can easily stuck there and create problem.. can this gap be avoided?

If there is crack on the root (MB), will the root always need to be wholly removed, even if the crack is horizontal?

I was told that my bone will grow into the space where the to-be-removed root is (I guess it is the "resulting socket"). Do I miss anything here? Is socket graft same as bone graft? It sounds like a filling (sorry for my ignorance)...

Were you talking about the "post" in the 3rd picture? I was told it was to take pictures inside the root. and there is no such post in the 4th picture.

Can you tell from the radiographs if the crack had existed even before the RC retreatment? Or was the RC retreatment necessary or properly conducted? Will RC retreatment necessarily result in wider root canal?

many thanks!
sbbi

 

[Laurence Stein DDS]

One question at a time.

After the removal of the root there will be a socket. It will heal and remodel over about a 3 month period. You can help direct and speed up the remodeling with a socket graft. If you're not contemplating a future implant, then the graft is not absolutely needed.

No matter the direction of any potential root fracture, the entire affected root must be removed.

The tooth will very likely need a cap to restore it. The shape of the crown will minimize the appearance of the tissue defect.

A socket graft is a bone graft that has been placed into the socket left after a tooth extraction. It may also be call socket preservation.

A post or endopost is a metal, ceramic or fiber post inserted into one of the canals after the completion of the root canal. It is used to reinforce the core and increase the retention of the core. When there is a large bulk of tooth remaining, a post may not be used. In teeth where the canals are large and therefore subject to fracture during the insertion of the post, it is probably better not to use one. You x-rays show that no post has been placed into the tooth at the time the radiographs were taken.

Fractured teeth or roots almost never show up in x-rays and it is not possible to determine if one existed before or after the root canal procedure. Even if a fracture occurred after treatment, it may not be caused by the procedure. Remember the tooth is brittle. Sometimes a fracture can be visually detected by the dentist during the root canal procedure... especially if an operating microscope is used.

Retreatment of a root canal may unavoidably widen the diameter of the canals when the treatment is completed.

 

[sbbi]

Hi Dr. Stein,

Thank you again for taking time answer my questions one by one.. I have been very worried and scared. I appreciate from the bottom of my heart.. How I wish I live in Miami!

The periodontist told me today over the phone that he seriously doubt that root amputation is viable.. He believes root extraction is needed after opening the gum.. It sounds like he suspect all of the roots in tooth #3 have cracked. My heart sank. I am also confused since my endodontist was suggesting root amputation. Could you pls explain, when the gum is opened, which signs/facts would make root amputation an impossible solution and make extraction unavoidable?

Thanks so much again!
sbbi

 

[Laurence Stein DDS]

sbbi,

Remember, I told you a root amputation is a "bail out" procedure. It helps you keep a tooth a bit longer but probably not for life. In addition, it can be useful to extend the life of, let's say an overlying crown or bridge that has already been completed.

If the tooth is truly hopeless, then bailing it out is counterproductive, more costly over the long haul and may limit future treatment options.

An amputation would not be a good treatment if there is an existing periodontal lesion associated with the remainder of the tooth, if the tooth is mobile before surgery, if there is a fracture that extends between the roots, if the removal of the single root will result in a remaining tooth that becomes mobile or if the remaining tooth is not really restorable with or without the root removal or if the root canal therapy is failing.

These are some but not all examples of why root amputation may not be recommended.

Just because you can do a procedure does not make that treatment appropriate.

There appears to be a difference of opinion between the two specialists. This can be normal. Why not ask your regular dentist (non-specialist) for an opinion.

Unfortunately, I cannot examine you so anything I may write to you is without benefit of a hands on evaluation. Let your dentist help you make the decision. He is there and can evaluate all the facts.

 

[sbbi]

Hi Dr. Stein,

Thanks again.. The periodontist told me that the bone will grow into the resulting socket after the root is removed.. but another periodontist i saw today said it may not be the case, and he said the bone would be resorbed over the time without graft.. I am just confused. could you pls explain?

If I choose to do implant directly now, do I still need bone graft after extraction for molar like tooth #3? I understand the implant will be done 3 months after the extraction, so i wonder if bone graft (or socket preservation) is necessary?
Thanks.
sbbib

 

[Laurence Stein DDS]

Following an extraction the bone will indeed grow into the socket. The problem is that you must rely on the random healing of the surgical site. If you place a socket graft, the material inserted into the socket helps to determine where the bone grows. There is less randomness.

This is good when you are planning an implant because you need good supporting bone in the future implant site.

So it is my "preference" that if an implant is planned to be used or even if it might be used, graft the socket. Typically, there will be more bone available when the implant is actually placed and that is a good thing.

Over time, bone that does not support a tooth or implant will slowly resorb. We cannot predict the speed or the amount of bone that may be lost. Grafting the socket generates more available bone but if you do nothing after the graft, it will slowly disappear. Generally, you have several years to re-establish implant function in order to maintain the bone.

If you choose to extract the entire tooth now, then you do socket preservation (for all the roots of this tooth). You then must wait 3 months for the bone to heal and become solid enough for implant placement. After 3 months, an implant is placed and typically another 3 months is allowed for the implant to integrate with the bone. Then you make the crown that goes onto the implant.

Rarely, is an implant placed into the socket left behind by a MOLAR extraction. A MOLAR socket is typically too wide and any implant placed immediately following molar tooth extraction most likely will not be tightly screwed into the socket.

Sometimes and I say this with caution, it is possible to immediately place implants into a fresh extraction socket. The implant must be wider than most of the socket to engage the surrounding bone. Even then some graft material may have to be placed around the opening of the socket, between the implant and the socket to "take up the space" between socket walls and the smaller diameter of the implant.

If the implant cannot be placed with good initial stability (tightness) then don't place it into a fresh extraction socket.

Now, sbbi, I think it is important that you have a good talk with your dentist(s). Some of the questions I am answering here should be explained by them to you. While I don't mind explaining on this forum, I should not be providing individual advice because I have never examined your mouth or reviewed your radiographs or history. That is what your personal doctor is there for. Hope you understand.

 

[sbbi]

Thank you so much Dr. Stein.. I totally appreciate all your suggestions..

I do like to discuss with my dentists, but the thing is they are very difficult to reach. it is difficult to find a good/caring dentist especially since tooth is not reversible.

Thanks again.