Root Canal Retreatment in Johnson City, TN

Medically reviewed by Riley Sturgill, DMD, MSD, an endodontist who teaches in Virginia Commonwealth University's endodontic residency program. Last reviewed: August 2026

You already did this once. The afternoon off work, the crown you paid for out of pocket. Now the tooth aches when you bite down, or there's a small bump on the gum that keeps coming back, or your dentist looked at an X-ray and said a word you didn't expect to hear again.

That is a discouraging place to be, and most people's first question is whether somebody botched it. In most cases, no. A tooth can be treated carefully and still go bad months or years later, for reasons that have less to do with technique than with anatomy and time.

The harder question is whether it's worth going through again. Often it is. A root canal that didn't heal is not the end of that tooth, and a lot of our patients walk in holding a recommendation to have it pulled.

What Root Canal Retreatment Actually Is

Root canal retreatment is a nonsurgical procedure for a tooth that didn't heal as expected, or developed a new problem, after an earlier root canal. The endodontist removes the original filling material from the canals, searches for anatomy the first procedure couldn't reach, disinfects the canal system again more aggressively than the first time, then reseals the tooth.

Whether it's the right call depends on the root, the crown, the bone around it, and how much healthy tooth is left.

Signs a Previous Root Canal May Not Be Healing

Some show up within weeks. Others surface years later, long after you'd stopped thinking about that tooth.

• Aching or tenderness when you bite or chew
• A dull pressure or throbbing that comes and goes
• A pimple-like bump on the gum near the tooth that drains, disappears, and returns. That's a sinus tract, a small channel the infection creates to relieve pressure.
• Swelling in the gum, cheek, or jaw
• The tooth feeling taller than the ones around it
• Nothing at all. Some teeth that aren't healing produce no symptoms and only turn up on routine imaging, or during a workup for something else entirely.

A recurring gum bump counts even when it drains and the pressure eases. The relief means the infection found an exit, not that it resolved.

Why a Treated Tooth Can Develop New Problems

A root canal fails for one underlying reason: bacteria are still living somewhere in the canal system. Everything below is a different route to that same problem.

The most common one is persistent bacteria. Some strains survive the first round of disinfection and stay in the canal system afterward, resistant to what was used on them the first time. That isn't a mistake anybody made. It's a stubborn population of bacteria that needs to be disinfected again, more aggressively, which is most of what retreatment is.

Anatomy is the next reason. A molar root isn't a straight tube. It branches and curves, and it sometimes hides a canal so narrow and deep it doesn't register on a flat X-ray at all. Upper first molars commonly carry an extra canal inside one of their roots, often calcified, often sitting right where it overlaps other anatomy on a two-dimensional image. Finding it reliably takes magnification and imaging built for that job.

Then there are the reasons that have nothing to do with the root canal itself, where bacteria get back in later:

• Coronal leakage. The seal between your crown and the tooth breaks down over time, and bacteria work their way back down into canals that were cleaned perfectly well the first time. This can happen months or years after the original treatment.
• New decay. A cavity forms at the margin of the crown and reopens a path for bacteria.
• A crack. A fracture in the tooth or root lets bacteria in continuously. A vertical root fracture is also one of the clearest reasons a treated tooth can't be saved, which is why we look hard for cracks before recommending anything.
• A delayed crown. If the permanent restoration went on months after the root canal, the tooth was exposed longer than it should have been.

Questions about the original treatment are fair to have. What we can tell you is what's happening now, and whether the tooth can still be saved predictably.

How We Determine Whether Your Tooth Can Be Saved

A traditional dental X-ray flattens a three-dimensional root into a single image. Missed canals sitting directly behind other canals disappear. Small lesions at the root tip hide behind bone. That limitation is a major reason failing root canals go unexplained for so long.

The American Association of Endodontists and the American Academy of Oral and Maxillofacial Radiology recommend limited field-of-view CBCT when evaluating previously treated teeth that aren't healing, and for spotting complications that change retreatment planning. Cone beam computed tomography builds a three-dimensional volume of your tooth and the bone around it, which we can rotate and slice through.

Every retreatment evaluation here includes a CBCT scan, which shows the root in three dimensions instead of one flat image.

Here, 3D imaging is part of every retreatment evaluation rather than an optional upgrade. The scan covers a small area around the tooth, and your doctor will show you what's on it and how it changes, or doesn't change, the recommendation.

We also treat under a dental operating microscope. Retreatment is really a search: the whole question is what the first procedure couldn't see. High magnification with coaxial light is how a canal that's been hidden for a decade finally gets found. You can see the equipment we work with on our endodontic technology page.

Retreatment, Apicoectomy, or Extraction

If extraction has been recommended, get an endodontic evaluation before the tooth comes out. Extraction is permanent, and it usually starts a second course of treatment rather than ending one.

There's no default answer here. The scan and the exam decide it.

We're not going to tell you every tooth is savable. Some aren't. A tooth with a vertical root fracture, too little structure left to hold a restoration, or advanced bone loss around it is a tooth we'd rather see replaced than retreated. Spending your money on a procedure we don't expect to hold isn't a favor to you. If that's what the imaging shows, we'll explain why and go over the replacement options, including a referral for extraction.

What tips the decision toward retreatment:

• The scan shows a canal that was missed, or a lesion consistent with persistent infection
• Enough healthy tooth structure remains to rebuild and restore
• The gum and bone support around the tooth are healthy
• No fracture running down the root

The thing that most often tips it the other way is a crack. If you'd like to understand how fractures behave and why they're so hard to catch, we go into detail on cracked tooth treatment.

What Happens During Retreatment

1. We reopen the tooth, usually through the existing crown.
2. We remove the existing root filling material from the canals that need retreatment.
3. We search the canal system under the microscope for anything untreated, guided by what the scan showed.
4. The canals are cleaned and disinfected.
5. The canals are refilled and sealed, and the access opening is closed.

One or two visits covers most retreatments. A larger or more stubborn infection may call for medication placed inside the tooth between appointments, then a second visit after whatever interval your doctor recommends. The whole thing runs longer than a first root canal because getting old filling material out takes time and care. Posts, crowns, calcification, and complex anatomy can stretch a case further, and we will tell you what to expect for your tooth when we schedule it.

If you've never had the underlying procedure explained end to end, our page on root canal treatment walks through the first-time version.

Will my crown have to come off?

Not always. When a crown is stable and well sealed, we can often reach the canals right through it and close the opening afterward. A crown needs to come off when there's decay underneath it, a failed seal, damage, too little tooth structure left, or a post blocking safe access.

When the exam and imaging suggest the crown or a post will complicate things, we'll say so before treatment rather than during. Occasionally a restorative problem only becomes clear once we're inside the tooth. If that happens, we stop and talk it through with you.

Will I need to go back to my dentist afterward?

It depends on the tooth and on your dentist. In many cases we place the final restoration ourselves before you leave, so no follow-up appointment is needed. Some general dentists prefer to place the final restoration themselves, and when that's what your dentist wants, we send you back to them and pass along everything they need.

Recovery

Soreness for a few days is normal, especially around the ligament that holds the tooth in its socket, which gets irritated during treatment. Your post-treatment instructions will name an over-the-counter option, assuming it's safe for you to take. That handles it for most people.

Follow the chewing guidance you're given for your specific restoration. If a temporary filling is in place, keep hard and sticky food off that tooth until the permanent one goes in.

Most people go back to work the same day or the next, depending on how they feel and whether they had sedation. Call us if pain increases after the third day, if swelling appears or worsens, or if a temporary filling comes out.

How Successful Is Retreatment?

The most-cited long-term work on this is the Toronto Study out of the University of Toronto, which followed retreated teeth for four to six years. Across its pooled phases, 82% had healed. Broader reviews that combine many smaller studies land anywhere from 71% to 87%, mostly depending on how strictly each one defined healing.

Those are averages, not a forecast for one tooth, and the Toronto data is useful precisely because it shows what moves the number. Teeth with no visible lesion at the root tip going in healed at 93%, compared with 80% for teeth that had one. Teeth without a perforation healed at 87%, against 56% for teeth with one.

After we review your exam and scan, we can tell you which of those findings apply to your tooth.

When nonsurgical retreatment isn't appropriate, or doesn't resolve the problem, endodontic microsurgery may be the next option. It's also called an apicoectomy, and it seals the root tip from the outside through a small incision. Sometimes extraction is just the better bet, and we'll say so. Dr. Colton Fischer completed additional microsurgery training at the University of Pennsylvania School of Dental Medicine and is a board certified Diplomate of the American Board of Endodontics, so a surgical case doesn't mean leaving the region.

Will It Hurt More the Second Time?

This is the question people are most embarrassed to ask and most desperate to have answered.

Many patients find retreatment easier than their first root canal, because the inflamed nerve tissue that made the tooth so sensitive originally is already gone. It does vary, particularly when the surrounding tissue is already irritated. What you should feel is pressure and vibration, not sharp pain. Getting fully numb is occasionally trickier when there's active infection, so tell us the moment something hurts. We'd rather stop and fix it than have you white-knuckle through.

A second round also carries a different kind of weight than the first, and we know that. If you've been dreading this appointment for weeks, the room is set up for it. Nitrous oxide sedation is available for an additional fee. Bose noise cancelling headphones and Netflix are there if you'd rather be somewhere else mentally. There's a massage chair, sherpa and weighted blankets, and memory foam neck and knee pillows, in every operatory. Mention nerves when you book and the visit gets planned around them.

Cost and Insurance

Retreatment typically costs more than a first root canal, mostly because it takes longer. Old filling material has to come out before anything else can happen, and a canal system that's already been altered is harder to clean than one nobody has touched.

We are out of network with all insurance plans, which means we do not bill your insurer directly. Our team helps you complete the paperwork so you can file with your plan and be reimbursed according to your out-of-network benefits. Plenty of plans still cover a meaningful share of endodontic treatment after the deductible, and you'll have a written estimate before you commit to anything. If you have questions about how your plan handles this, call the office before your visit and we'll go through it with you.

Extraction is rarely the end of the spending, though. A missing tooth usually needs replacing with an implant, a bridge that involves cutting down the healthy teeth on either side, or a partial. Each of those adds cost and follow-up beyond the extraction itself.

Why Patients Travel to Johnson City for Retreatment

We see patients from Kingsport, Bristol, Elizabethton, and across the state line from Abingdon and Southwest Virginia, who come here for specialty retreatment done with 3D imaging and a dental operating microscope. Our office is at 2800 Peoples Street, Suite 60.

Most of our patients arrive on a referral from their general dentist, and that's the route we'd point you toward first. Your dentist can look at the tooth and confirm the problem is actually endodontic before you spend a visit here. Not every ache in a treated tooth is a failing root canal, and it's better to find that out from the person who already knows your mouth.

If your dentist has already examined the tooth and recommended pulling it, that step is behind you. Call us directly and bring whatever they gave you.

Dr. Colton Fischer and Dr. Riley Sturgill. Both trained in endodontics at Virginia Commonwealth University.

Both of our doctors completed their endodontic residency training at Virginia Commonwealth University. Dr. Riley Sturgill founded this practice and teaches in VCU's endodontic residency program. If you want to understand what separates an endodontist from a general dentist and why that matters for a case like yours, we explain it on about endodontics.

Common Questions

Sources: Farzaneh M, Abitbol S, Friedman S, Treatment Outcome in Endodontics: The Toronto Study, Phases I and II, Orthograde Retreatment, Journal of Endodontics, 2004. de Chevigny C et al, The Toronto Study, Phases 3 and 4, Journal of Endodontics, 2008. American Association of Endodontists, Endodontic Retreatment Explained.