Erupting Compromised Teeth for Restoration by Dr. Joe Whitehouse

Erupting Compromised Teeth For Restoration 

by Dr. Joe Whitehouse


Periodically, a question comes up about how to restore a tooth that has very little clinical crown showing, usually because of clinical fractures or severe caries. These cases deserve to be considered for application of forced eruption. The issue becomes especially dire when:

  • The tooth was restored without enough ferrule effect, so the crown is in need of being recemented over and over because there’s insufficient retention.
  • A root-canaled anterior tooth with a post and core comes out because of a short post and a ferrule issue.
  • The patient presents with severe decay or a fracture.
  • The root splits because a crown build-up with a post has been torqued out, splitting the root with no option but extraction.
“Why not just put in an implant?” That may seem like a fair option until other issues come up, including time, money or attitude (both patient and dentist). For circumstances where saving the root is appropriate, I offer eruption as a very predictable clinical course.

Determining and setting expectations
I always start a project/treatment by focusing on what outcome the patient expects. That outcome also may affect you if there is an ongoing issue with the treatment, such as failure in some way. Here are my concerns:
  • Durability. How long will what I do last? It would seem that placed crowns are meant to last indefinitely, but when you look at Figs. 1 and 2, you can see the outcomes were not planned properly. This case was only one month old.
  • Patient buy-in. In my conversations with patients, I always ask, “How long would you like what I do for you to last?” The more you can make your patients feel involved in their treatment, the more trust is built.
  • Function. Will the treatment lead to the patient’s idea of proper functioning? Most patients are going to prefer it if you can put back an individual tooth, rather than creating a bridge. (Think: flossing.)
  • Aesthetics. It’s always better when a restored tooth is in the mouth; not planning for the longest term of completed care compromises this. Also, aesthetics around anterior implants can be tricky because the patient always wants the outcome to look at least as nice as it was before the issue of which we are speaking comes up.
  • Price. What value are the patients willing to place on the outcome they desire?
  • Methodology. Is the patient willing to wear braces to get the best outcome?
  • Time frame. How long will it take to get the best outcome (or the one the patient wants)?
From my perspective, erupting anteriors or bicuspids has made great sense to getting the outcome that patients appreciate and for which patients are willing to pay. Let’s continue with the case from above to make this point.

When the patient presented with the previous dentist’s attempt to restore, as seen in Fig. 1, she was worried about what outcome was possible. Having performed similar procedures many times to get the outcome she wanted, I was able to show her photos of completed cases, which helped her trust the coming process.

I always ask, “How much would you like to know about the treatment I’m going to recommend?” Some patients want no information—“Just go ahead, doctor”— while others want as extensive an explanation as possible. This particular patient said what we’ve all heard many times: “Go ahead with that treatment. I trust you.” (Music to my ears!)

Erupting Compromised Teeth For Restoration
Fig. 1
Erupting Compromised Teeth For Restoration
Fig. 2


The process
The first issue is getting out the now-fractured post. This can be a real bearcat; in my experience, ultrasonics work best to loosen them. Be careful not to perforate the root! Once out, a new post (Fig. 3) is placed—ideally as long as possible without compromising the lower root. Metal or fibrous, choose what you like.

A core is now placed around the post and contoured to look like a tooth (Fig. 4), to which the bracket will be placed. This needs to look similar to the other central. Fig. 5 shows the brackets in place. Please, do not let this minor use of orthodontic brackets bother you! They are very simple to place if done properly.

Erupting Compromised Teeth For Restoration
Fig. 3
Erupting Compromised Teeth For Restoration
Fig. 4
Erupting Compromised Teeth For Restoration
Fig. 5


1. Etch each tooth well where the brackets will go. If there is a crown involved, sandblast the area and etch with a porcelain etch, use silane and bond. Once the tooth has been etched, you can use bracket cement or plain composite pushed into the bracket grid, held in place and cured. Get the slot parallel to the incisal edge.

2. Note how the subject tooth has the bracket placed above the side brackets. The side tooth brackets are either centered or toward the incisal; the distance between them is the amount of supereruption to be accomplished. By this, I mean if I want a 3 mm ferrule effect, I will need to bring the root down that much, so if there is 3 mm of distance between the center groove of the brackets up/down, the root will be erupted that distance. If further eruption is needed, you will put the wire on top of the subject tooth’s bracket for more eruption.

3. When “loading” the orthodontic wire, it needs to be cooled so it will be flexible (Fig. 5). Make a stick of ice from a needle cap or buy an ice pen. Round wire of 0.014-inch titanium is easier to manipulate, but rectangular wire will move the teeth quicker. Some teeth will come down surprisingly quickly, and that’s OK! Others, like cuspids, usually take longer.

4. The final procedure is to sever the ligament all around the tooth (Fig. 6) to keep the bone from advancing down. Use an #11 or #12 blade. (I am showing how to do this if you don’t have a laser— the way I do it.)

5. Finally, make sure to remove from the lingual and perhaps incisal built-up composite that will interfere with the eruption, because teeth can advance down more rapidly than one might expect.

All the treatment up to this point has been accomplished at the first appointment. The next time you see the patient, ideally, is when the subject tooth is hitting the opposing arch. Just remove more composite.

Erupting Compromised Teeth For Restoration
Fig. 6
Erupting Compromised Teeth For Restoration
Fig. 7


Compare the movement from Fig. 7 with Fig. 6. The orthodontic wire, being nickel-titanium, wants to straighten out, like magic. When this point arrives, there are two options:

  • The process is complete as to movement.
  • If you want to move the tooth down/up (for lower anteriors) more, put the wire on top of the bracket for more extrusion for a greater ferrule effect. Remember, as the wire straightens out, it will protrude out the distal side of the outer brackets. Be prepared to trim that back as needed.
The final critical issue is retention. The root will retrude into the socket if not held long enough at the final spot. (This happened to me once after the crown was on and the incisal edge moved up—embarrassing! I had to erupt the new crown down with same technique.)

The amount of time is subjective because each patient’s movement will be different, but the longer you can get the patient to stay in retention, the better—say, six weeks. (If a patient is pushing to get the brackets off, just mention what can happen and ask if he or she wants to go through that.)

Figs. 8 and 9 (from a different case) show the build-up prepped, and a very adequate ferrule effect will protect the core and post. Fig. 10 is the final outcome. If you have a long cuspid, bring the root down more if you like, as seen in Figs. 11–14.
Erupting Compromised Teeth For Restoration
Fig. 8
Erupting Compromised Teeth For Restoration
Fig. 9
Erupting Compromised Teeth For Restoration
Fig. 10
Erupting Compromised Teeth For Restoration
Fig. 11
Erupting Compromised Teeth For Restoration
Fig. 12
Erupting Compromised Teeth For Restoration
Fig. 13
Erupting Compromised Teeth For Restoration
Fig. 14


Other examples
Cuspids and bicuspids are also candidates for this type of treatment. Figs. 15–17 show another case, with Fig. 17 ready for a crown impression. Figs. 18, 19 and 20 show tooth #29 receiving the same treatment. (Note the ice pen in Fig. 19 for softening the wire.)

Erupting Compromised Teeth For Restoration
Fig. 15
Erupting Compromised Teeth For Restoration
Fig. 16
Erupting Compromised Teeth For Restoration
Fig. 17
Erupting Compromised Teeth For Restoration
Fig. 18
Erupting Compromised Teeth For Restoration
Fig. 19
Erupting Compromised Teeth For Restoration
Fig. 20


Considerations
  • Crown-to-root ratio. I have researched this with no firm final ratio. I believe that a 1:1 root remaining in the bone to the prepped abutment seems to work. If cuspid rise is your occlusal philosophy, a shortrooted cuspid would need to be evaluated for this technique. Could there be less root in the bone? Perhaps, depending on the occlusion. An upper lateral with no anterior or posterior torque could be OK. A bicuspid with only vertical force should be OK. Occlusion can be adjusted to help with this issue.
  • Why not do crown lengthening? I am totally into minimally invasive approaches, and crown lengthening is a bit invasive and may affect the cosmetic view. Certainly, it is appropriate in the posterior, and I have done it there for more ferrule effect; however, in doing crown lengthening, one must consider the bone anatomy of the adjacent teeth. Also, critically, one cannot invade the biologic width—noted to be, on average, 3 mm. I have seen several incoming patients who had chronic inflammation where the margin of the crown was placed too close to the bone, invading the biologic width. These are the cases that should have had eruption as described in this article. (In fact, erupting biologic width crown invasion can be corrected by forced eruption.)
  • Up to this point, I have not mentioned a removable appliance technique. Yes, it is possible to erupt with an Invisalign-type appliance or a retainer, but the expense, time and predictability is, in my hands, not worth the effort.

Summary
Restoring fractured or severely decayed anterior or bicuspid teeth for a long-lasting predictable outcome can be compromised by how much tooth structure is left beyond the gingival margin to get a well-retained crown to stay in place indefinitely.

Of the choices to retain the root, supereruption is the least invasive technique to overcome the issue for sufficient retention of a crown. The technique is straightforward and accepted by most patients, and the outcomes are valued by patients.

When Not To Attempt Forced Eruption

  • The root or leftover tooth is too damaged, especially with decay up into the root area. (Even this is a bit subjective.)
  • The patient refuses to wear orthodontic brackets.
  • The patient has an implant, likes it and wants another.
  • The prognosis is too questionable for any “sure” outcome.
  • The patient can’t afford procedures, and wants no treatment or a temporary partial.
  • The patient wants an outcome ASAP— so, an extraction with bridge prepped the same day and temporized.
  • The root is too short, or split.
  • The root/crown break is above the bone line.

 
I would always recommend an implant over a bridge where two virgin teeth would need to be prepped. However, if the cosmetics could be vastly improved with a bridge, I do consider that.

Author Bio
Dr. Joe Whitehouse Dr. Joe Whitehouse graduated from the University of Iowa Dental School in 1970. During his career, Whitehouse brought three other practices into his own and adopted a totally minimally invasive approach to dental care. He was a co-founder of the World Congress of Minimally Invasive Dentistry, serving as president for two terms.
Whitehouse also earned a master’s degree in counseling, enabling him to treat many fearful/apprehensive patients without drugs. He has written about dealing with fearful patients and authored articles on minimally invasive dentistry and clinical issues dentists face.


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