Root Canal Retreatment

A root canal can fail years later, and most failed root canals can be redone. Retreatment means reopening the tooth, removing the old filling material, cleaning the canals again and resealing them. At Pearl32 Dentistry and Wellness in Laguna Hills, we start with a cone beam scan to find the reason. Common causes are a missed canal, a leaking crown, new decay or a cracked root. The scan tells us whether the tooth is worth saving.

Why does a root canal fail?

Four things cause most failures. A canal was missed, often a second canal in the front root of a lower molar. The seal leaked, usually under a crown margin or an old filling. New decay reached the canal from the outside. Or the root cracked under chewing load.

Time matters too. Bacteria need a path and they find one slowly. A tooth treated in 1998 may have been done well by the standards of that day, before magnification and three dimensional imaging were routine. That is not a failure of care. It is a tooth that now needs a second look.

What are the signs the tooth needs retreatment?

Pain on biting is the most common sign, and it is often mild at first. Other signs include a small bump on the gum that drains and refills, a bad taste, swelling that comes and goes, and tenderness when you press over the root. Some teeth have no symptoms at all.

Many failures are found on a routine x-ray. A dark halo at the root tip that is new or growing means bacteria are still active. We compare against older images when we have them. If the first root canal was done elsewhere, ask that office for your records and we will request them.

How does the cone beam scan change the plan?

A cone beam scan shows the root in three dimensions, which a flat x-ray cannot. Missed canals hide behind the filled canal on a two dimensional image. The scan separates them. It also shows the size of the bone lesion, the distance to the sinus floor and the nerve canal, and signs of a vertical root fracture.

The scan takes under a minute here in Suite 450. We use it when it changes the plan, not routinely. Read more about our digital imaging and about endodontic care.

Retreatment, apicoectomy or extraction: how do you choose?

Retreatment usually comes first, because it keeps your own tooth. The crown or filling is removed, the old material is taken out, the canals are cleaned and reshaped, and the tooth is resealed. A new crown normally follows.

When an apicoectomy fits

If the canal cannot be reached again, or removing a post would risk fracture, a visiting endodontist can remove the root tip through a small opening in the gum and seal the end. Healing takes a few weeks.

When extraction is the honest answer

A vertical root fracture, a perforation in a poor position or heavy bone loss changes the math. Then we discuss a dental implant instead.

What retreatment will not do

Retreatment will not regrow bone overnight, and it will not repair a fractured root. Bone fills in over six to twelve months once the infection clears, and we track it with follow up x-rays rather than guessing. If the lesion has not shrunk by twelve months, we reassess with you.

It will not always succeed. Retreated teeth do well, but the odds are lower than for a first root canal. We tell you the odds for your tooth before you decide, and we put the alternative plan and its cost in writing at the same visit.

What does root canal retreatment cost?

Cost depends on the tooth, the number of canals and whether the crown has to be replaced, and it is quoted in writing, itemized, after an examination. The scan and the new crown are listed separately so nothing is hidden inside a single figure.

We are in network with most major PPO plans and Delta Dental HMO. Plans often treat retreatment differently from a first root canal, so we send a predetermination when time allows. Third party financing is available and the practice is not the creditor, through CareCredit, Cherry, Sunbit and Happen Bank (formerly LendingClub). See financing.

Questions people ask about root Canal Retreatment

Why did my root canal fail after ten good years?

Usually the seal broke down before the canal did. A crown margin leaks, decay works underneath it, and bacteria reach the canal from outside. A missed canal can also sit quietly for years before it flares. Ten comfortable years is not a wasted investment. It usually means the tooth is worth a second attempt rather than removal.

Is retreatment more painful than the first root canal?

It is a longer appointment, not a sharper one. The tooth is numbed the same way and tested before we start. Removing an old post or crown adds vibration and time. Soreness afterward lasts two to four days and responds to ibuprofen. Nitrous oxide, oral sedation and IV sedation are available if the length of the visit is what worries you.

How successful is retreatment?

Published success rates sit around 70 to 85 percent, lower than for a first root canal. The number depends on why the first one failed. A missed canal that we can now find has a good outlook. A cracked root does not. We look at your cone beam scan and tell you which group your tooth falls into before you spend anything.

Should I just get an implant instead?

Sometimes, and we will say so plainly. An implant is reasonable when the root is fractured, when too little tooth remains above the gum, or when bone support is poor. It is a longer path: extraction, healing, placement, then a crown. When the tooth can be retreated with a fair outlook, saving it is usually simpler and faster.

Who does the retreatment?

Our general dentists handle most retreatments here in Suite 450. All three hold a DDS from Loma Linda University. Complex cases go to a visiting endodontist who comes to our office, so you are not sent across town. Dr. Nojan Jahedmanesh also holds a certificate in prosthodontics from UCLA, and he practices as a general dentist. We tell you up front which path your tooth needs.

This page is general information, not a diagnosis. What is right for you can only be decided after an examination.