Signs That a Tooth Just Can’t Be Saved

Sometimes it’s just unavoidable: no matter the clinician’s efforts, a tooth just may be unsalvageable. Knowing when that tooth is irretrievable can sometimes be obvious, but other times the signs may be subtle, and the endodontist will have to rely on experience and skills to recognize whether a tooth can be saved.

The Big Deal

The most obvious sign that a tooth just can’t be saved is when a root fracture exists.

“These findings are known as ‘J-shaped bone loss’ in a tooth that has had a root canal, especially if there's a post in place, especially in a patient that is a bruxer,” Brooke Blicher, DMD, an endodontist at Upper Valley Endodontics in White River Junction, Vermont says. “There's nothing else that this could be. And unfortunately, root fractures are one of those things that we just don't have interventions for. There are things that have been proposed in the literature, but I always tell patients that we don't have strong enough materials that can glue things together in a way that can support root structure, and reinforce this in a long-lasting way.”

Ryan M. Walsh, DDS, MS, Diplomate, American Board of Endodontics and endodontist at Advanced Endodontics of Texas in Keller, Texas, observes that cases are more readily diagnosed with the advent of better imaging.

“They seem to be more prevalent now than they were in the past, and maybe that's because we're better diagnosticians or we have better imaging,” he says. “But we tend to see those quite frequently. And often, we won't know for sure until we see a radiograph or a CBCT, and even then, we can't conclusively diagnose a fracture without opening the tooth and getting into it. Sometimes to definitively diagnose a vertical root fracture, we must already be inside the tooth and clinically see that fracture line extending into the radicular tooth structure.”

Fractures can exist anywhere on the tooth, and while they may not mean the end of the tooth above the gumline, root fractures will seal the tooth’s fate.

“Fractures come in many different shapes and sizes,” Dr Walsh says. “Crown fractures versus root fractures. Is it a split tooth or a cusp fracture? All those things go into the long-term prognosis of the tooth, and if the fracture is fully maintained within the crown or the chewing portion of the tooth, the long-term success is favorable. It's only those cases where it starts to extend down into the root structure and down below the bone that things really become a challenge to not only do a root canal, but to predictably save the tooth, long-term. Any time the fracture is extending into the root structure of the tooth below the bony support, I recommend extracting the tooth, because the long-term success is poor. I also don't want the patient to incur any other adverse impacts, such as additional bone loss or compromise adjacent teeth at the expense of a tooth that has a poor long-term success.”

“It's really the end,” Dr Blicher adds. “If there's any fracture into root structure, it’s going to get bigger over time due to biting forces, leading to a split tooth. The earlier we get these teeth out, the better. I hear from my periodontal and surgery colleagues that root fractures lead to dramatic levels of bone loss in very short periods of time, so the sooner we can get these teeth addressed and out of there, the more options the patient is going to have as far as doing an implant.”

Less Obvious

While root fractures are a very clear indicator that the tooth can’t be saved, there are other, more subtle indicators to be cognizant of.

“Even if there are deep caries, maybe we can save this tooth,” Dr Blicher says. “It really depends on several factors: Why is this patient getting such deep caries? Is it home care, dry mouth, or a systemic health issue? What's going to be the longevity? Is saving the tooth the right thing for this patient? Can this patient tolerate the treatments needed to save the tooth?”

The signs may not immediately indicate tooth loss, but it should remain an option, and it may be a decision that the patient prefers.

“I recently had a patient with a combined perio/endo infection,” Dr Blicher recalls. “He had an endodontic infection and a periodontal disease on the same tooth. These coalescing infections are harder to treat. In theory, it might respond to treatment, but the prognosis is reduced, the treatment might take a few visits, and periodontal therapies might be needed. Even still, the periodontal disease might limit long-term maintenance of the tooth. This patient travels all the time, and treatment with a reduced prognosis was too much for him to risk. He wanted to keep his highflying lifestyle and didn't want to have to worry about something failing, so we opted for extraction instead.”

Modern imaging technology helps dentists diagnosis these problems more efficiently.

“A major reason that my partner and I take CBCTs on most patients that we're working up for endodontic treatment, are incidental findings,” Dr Blicher says. “Things like undiagnosed root fractures, perio-endo infections, and resorption can really doom a tooth if we don't address them. Incidental findings can really change our treatment plans and make us less likely to recommend saving a tooth, because it's not going to reliably work, or the risk is going to be intolerable for that patient.”

It’s never a bad idea to ask for a second opinion or specialist’s expert eye.

“I don't know that there's a lot that's overtly missed, because some types of endodontic infection can mimic a vertical root fracture,” Dr Walsh says. “Any time a general dentist suspects a root fracture but can't conclusively diagnose, I feel it's worth referring to the endodontist for further imaging and/or further clinical evaluation to determine if it's truly a fracture. If it's just endodontic pathology mimicking a root fracture, the long-term success is favorable if we can treat the endodontic pathology. However, if we get inside the tooth and discover a deep root fracture, then the prognosis is poor and I would recommend extraction, but I don't think there's a lot of overt cases where dentists are missing things like this that are clearly non-restorable teeth.”

The Bad News

If a tooth is unsalvageable, it’s time to deliver the bad news. No matter how it’s done, it requires tact and finesse. For instance, Dr Walsh lays out the long-term costs and consequences of living with such a tooth.

“I like to think of it in this perspective: sure, we can treat that tooth for you, but the long-term success is poor,” he says. “How much time, money, and effort do you want to invest in a tooth that ultimately will need to be extracted? You don't want it to be maintained in the mouth at the compromise of potentially adversely impacting adjacent or opposing teeth. I think the best long-term success would be extracting the tooth and replacing it, rather than trying to maintain it.”

The more information of patient has, adds Dr Blicher, the better decision they can make.

“Part of it is just laying it out there for the patient and being honest and objective,” Dr Blicher says. “But part of it is having them as part of my exploration and discovery, so I know they're on board. As I go through my diagnostic workup, I’m explaining everything. I have a really detailed, informed consent discussion with patients, and I'm always giving them options. Even if a tooth is, technically speaking, salvageable, I'm telling the patient about their options for extraction or non-treatment, including their risks and benefits, to try and make this a tenable decision for them to make. I'm a specialist, so I'm really only equipped to offer endodontic care. But I'm talking about the whole picture with patients because it matters, and it's also a way to build relationships with patients that I don't have a lot of time with. I spend a lot of time talking with people.”

Communication is also very important with the referring doctor, as they are the ones who must continue the patient’s care.

“We always call the general dentist’s office because many general dentists extract teeth and nowadays many place implants,” Dr Walsh says. “I always like to talk to the general dentist first, because they're the quarterback of the team, and are the lead restorative expert in the case. If they'd prefer to refer it to an oral surgeon or a periodontist, I'm happy to provide that referral, but I always want to touch base with the general dentist first before referring them to anybody else's care.”

“I don't do any extractions in my office,” Dr Blicher adds. “I always briefly review with patients their replacement options, and that's what I put in the note back to the dentist. I say, ‘We briefly reviewed the options of not replacing versus fixed options versus implant replacement versus removable.’ As an endodontist who doesn't do extractions, I have that ability to go through the broad scoping details of treatment options while deferring to the experts. Ultimately, what comes next depends on the referring office I'm working with. Some offices prefer that I send patients directly back to them, and then they either extract teeth or they make referrals from there. Some offices ask for direct referral to oral surgeons. In my community, we are lucky to have some great oral surgeons and periodontists that I'll refer directly to. Even if a tooth is, technically speaking, salvageable, it's ultimately the patient's choice what they want to do. I always want to make sure that I communicate that to the patient that the ball's in their court. I'm not here to sell them on a root canal or saving a tooth. I want them to reach that decision on their own.”

The signs are there. Sometimes they are obvious and unavoidable. Other times, it requires further examination to make an unfortunate diagnosis. Whatever the case, it is up to the patient to decide whether they want to save a tooth, and it’s up to the endodontist to help guide that decision.