What Makes A Tooth Non-Restorable?
posted: Jul. 10, 2021.
A question that I had come up this week is "what does non-restorable mean in a dental context?".
The basic answer is that non-restorable means that a tooth or appliance cannot be restored to adequate function or usability. The questioner went on to ask for more details about why this would happen. I thought I'd also share my answer with you.
In order to restore a tooth, we need a certain amount of tooth structure available to hold the filling or crown. Generally speaking, the more tooth structure you have, the better. In school, we were taught that a minimum of 2-3mm height above the gumline is needed for a crown. So if a tooth is broken off at or below your gumline it is probably non-restorable. (Note: In some cases heroic measures can be taken to try to restore your tooth, but I always warn that there is no guarantee of how long these heroic measures will hold up.)
What are those "heroic measures"? First, you would need to see if your tooth is a candidate for a crown lengthening procedure. Crown lengthening is a surgery to expose more tooth structure above your gumline to try to get that 2-3mm that we need. This surgery involves both the bone around your tooth and the gums around your tooth. But we also need to be careful to leave enough support for your tooth (more on that later). IF your tooth is a candidate for crown lengthening surgery, then you'd also need to get a root canal done on the tooth. The root canal is needed for two reasons: first, if you've broken your tooth off to this point, then the dental pulp is probably already exposed to the bacteria in your mouth and already infected and second because we need the extra surface area that being able to use the pulp canal provides. After the root canal, you would need a post & core procedure. The post part is what goes down into the pulp canal (it is cemented there) and the core part is what builds up the part of the tooth above the gumline to provide something for the final restoration to grip. Post & cores can be one piece (custom cast for your tooth by a dental laboratory or milled in a CAD/CAM machine) or be separate pieces (a pre-fabricated post cemented in place with a restorative material built up around it). I tend to prefer the one piece ones for severely broken down teeth because it means there is one less junction for the final restoration to fail around. Then, as the final restorative step, you would need a crown.
Now that we have dental implants available, if you are a candidate for those, they are a much more reliable long-term restoration than heroic measures. Yes, dental implants are expensive--but so are heroic measures.
Another reason that a tooth may be non-restorable is if there is not enough bone support for it. Our teeth are held in our jaw by the bone around them. If bone is lost, either due to gum disease or trauma, then the tooth becomes mobile or loose. Right now, we do not have reliable methods to replace bone around a tooth when it has been lost to gum disease. So if a tooth does not have adequate supporting structures, it may not be able to be restored.
Teeth are not the only thing that may not be fixable. Dental appliances (dentures, partials, retainers, splints, etc.) may also break in ways that cannot be repaired. Remember that any time an appliance breaks, even if it is repaired, that area is now a weak point that can break again or cause another spot to break.
If your appliance has broken, generally the bigger the pieces you have, the more likely it can be repaired. I remember once having a patient bring me pieces of an appliance that her pet had chewed up. Most were tiny fragments and none of the pieces were recognizable enough to orient where they would have been on the original appliance. That's an extreme case, but it's one we weren't able to repair--meeting the criteria for non-restorable.
If you haven't worn your appliance for a while, your teeth may have shifted or moved so that the appliance no longer fits. If we're able to get it to fit you again, we've probably removed quite a bit of material from the appliance which could compromise looks or comfort as well as strength of the material.
Remember that each person is unique and the information presented here is general. Your dentist will be able to evaluate your specific situation and provide you with an opinion and the options that you have. If you're unsure, you can also always seek a second opinion for another dentist or dental specialist.
Note: The information in this article is not meant to replace the clinical judgement of your health care professionals.
Jennifer G. Robb, DMD is a general dentist who sees both adults and children at her office located at 1320 Cooper Foster Park Rd. W, Lorain, OH 44053. Call 440-960-1940 for appointments.