Root canal treatment
Root canal treatment in Otemachi, Takebashi and Jimbocho
Root canal treatment in Otemachi
(nerve treatment)
Hamille Tokyo Dental Office
Root canal treatment is, in a sense, the last line of defence against tooth decay that has reached the nerve — treatment aimed at keeping your own tooth rather than extracting it.
What is root canal treatment? Treatment that saves your tooth
What root canal treatment involves
Root canal treatment cleans out the canal that houses the nerve and removes the bacterial infection inside it. It is needed when tooth decay has reached the nerve, or when pus has built up at the tip of the root of a tooth treated in the past.
Inside a tooth there is a chamber called the pulp, containing nerves and blood vessels. Once this becomes infected with bacteria, it causes severe pain or swelling. Root canal treatment removes the infected pulp, cleans and disinfects the inside of the canal, then fills it with a sealing material, aiming to save the tooth without extraction.
The stage of decay at which root canal treatment is needed
Tooth decay progresses from the enamel on the surface of the tooth into the dentine, and then gradually into the nerve (the pulp). While it stays within the enamel or dentine it can be treated with a filling, but once bacteria reach the nerve, a filling is no longer enough and root canal treatment is needed. Left untreated further, so that the tooth breaks down extensively, extraction may eventually have to be considered.
Signs that root canal treatment may be needed
Throbbing pain even when you are doing nothing, sharp pain on hot or cold food and drink, pain that gets worse at night and keeps you awake, a jarring pain when you chew, swollen gums with a lingering foreign-body sensation — any of these can be a sign that the nerve is inflamed or infection is developing at the root tip. If any of this sounds familiar, we recommend coming in as soon as you can.
Why root canal treatment becomes necessary
Cause 1: Decay reaching the nerve
As decay advances, bacteria reach the nerve. At this stage, sharp throbbing pain can continue even without doing anything, and hot or cold food and drink can trigger intense pain. Pain can also worsen at night, disrupting daily life considerably. When these symptoms appear, root canal treatment is needed to remove the nerve.
Learn more about cavity treatment
Cause 2: Pus at the root of a tooth that has already had the nerve removed
Even a tooth that has already had nerve treatment can develop pus at the root tip over time if bacteria remain there — a condition called apical periodontitis. Symptoms include pain on biting, swollen gums and a sense of something foreign in the area.
Left untreated, the abscess can grow larger and may even cause swelling across the face or loss of jawbone. In this situation, the root canal needs to be treated again to clean out the inside of the canal once more.
Cause 3: A cracked tooth or injury
A strong impact to a tooth, from a fall or an accident for example, can chip or crack it. If this exposes or damages the nerve, root canal treatment may also be needed.
Learn more about oral surgery
Do you have any of these symptoms?
- Throbbing pain continues even when you are doing nothing.
- Pain when chewing, and swollen gums.
- A lingering foreign-body sensation after a knock to the tooth.
4 types of root canal treatment
Root canal treatment is a general term, but the approach differs according to the tooth’s condition. It broadly falls into the 4 types below.
Type 1: Pulpectomy (removing the nerve)
This treatment removes a nerve that has become severely inflamed because of decay or injury. It is used on teeth where the nerve is still alive, removing the cause of the pain while aiming to keep the tooth itself.
Type 2: Infected root canal treatment (draining pus)
This treatment is for teeth where the nerve has already died and bacteria have multiplied inside the canal, or where pus has built up at the root tip. Infected tissue is removed, the inside of the canal is cleaned and disinfected, and the cause of the pus is gradually eliminated.
Type 3: Root canal retreatment
This treatment is for a tooth that has had root canal treatment before and has become infected again: the crown, post and core are removed, the earlier filling material is taken out, and the inside of the canal is cleaned again. It is usually more complex than the first treatment and calls for more time and more careful work.
Type 4: Apicoectomy (surgical treatment)
When standard root canal treatment brings no improvement, or the lesion at the root tip is large, a surgical procedure called an apicoectomy may be carried out. It removes the root tip itself along with the lesion.
We perform apicoectomy depending on the case. If more specialised treatment is needed, we will refer you to an appropriate institution. Please talk to us first.
Why root canal treatment recurs so often in Japan
Root canal treatment is a type of treatment where problems can recur some time afterwards, and recurrence is not uncommon. The main causes can be summed up in the 3 points below.
Cause 1: Bacteria left inside the canal
Root canals are narrow, often curved and branching, with a complex structure. If bacteria remain in a spot that is hard to see with the naked eye, it can cause inflammation to return later.
Cause 2: Reinfection from saliva during treatment
Saliva contains large numbers of bacteria. If saliva gets into the canal during treatment, a canal that has been carefully cleaned can become infected again. This is why moisture control during treatment matters.
Cause 3: Bacteria entering through gaps in the filling
If there are gaps in the material filling the canal or in the crown, bacteria can get in through them and cause inflammation at the root tip again. Both a tight, gap-free filling and a high-precision crown are key to preventing recurrence.
What sets our precision root canal treatment apart
Feature 1: Viewing the canal magnified under a microscope
We use a dental microscope to magnify the inside of the canal before treating it, allowing careful work on details that are hard to see with the naked eye. This reduces bacteria left behind and helps lower the risk of recurrence.
Feature 2: Mapping the root’s shape in 3D with dental CT
Taking a dental CT scan in addition to an X-ray lets us see the number of roots, how they curve, and the size of the lesion in three dimensions. How precisely we understand the shape directly affects how precise the treatment plan can be.
Feature 3: Keeping saliva out with a rubber dam
Depending on the case, we carry out root canal treatment with moisture control using a rubber dam. A rubber dam is a thin rubber sheet that isolates just the tooth being treated, keeping out saliva and bacteria.
For root canal treatment to succeed, keeping the inside of the canal sterile matters. Saliva carries large numbers of bacteria, and if it gets into the canal during treatment it can cause reinfection. Using a rubber dam lets us treat in a clean environment, improving the chances of success.
Feature 4: Handling complex canals with NiTi files
Highly flexible nickel-titanium (NiTi) files follow curved canals more easily, allowing thorough cleaning even where the canal shape is complex.
Feature 5: Sealing the canal tightly with MTA material
Depending on the case, we use MTA material, which seals well and is highly biocompatible, to close the canal tightly and avoid gaps that would let bacteria back in.
The root canal treatment process
Step 1: Examination, diagnosis and explanation
We first ask about your pain and any earlier treatment, then take X-rays and a CT scan to check the shape of the root and the size of any lesion. Based on the findings, we explain in detail why root canal treatment is needed, how it will proceed and roughly how many visits to expect. Please feel free to ask us anything at any time.
Step 2: Anaesthetic and removing the infected area
After the anaesthetic takes effect, we remove the decayed part of the tooth and the infected nerve. Depending on the case, we use a rubber dam for moisture control, treating the tooth while keeping saliva out.
Step 3: Measuring the length of the canal
We use an apex locator to measure the length to the root tip accurately. The beeping sound you hear during treatment is this device at work — it does not cause any pain, so there is nothing to worry about.
Step 4: Cleaning and disinfecting the inside of the canal
We clean the inside of the canal thoroughly with dedicated instruments, then wash and disinfect it with a medicated solution. To avoid leaving infection in even the smallest areas, this step is repeated several times to keep the canal clean.
Step 5: Filling the canal (sealing with material)
Once the inside of the canal is clean, we fill it with the final sealing material to keep bacteria out. Filling it without leaving any gaps is a key part of preventing recurrence.
Step 6: Fitting a post and core, and a crown
We build up a post and core, then restore the tooth with a crown to bring back its original shape and function. You can choose anything from insurance-covered materials to self-pay ceramic, according to your wishes.
Learn more about ceramics and crowns
How many visits and how long root canal treatment takes
How many visits will it take? — this is one of the questions we are asked most often about root canal treatment. Below is a rough guide by type of treatment.
Number of visits for a pulpectomy
For pulpectomy, removing the nerve, a few visits is a general guide. If the inside of the canal is stable, we can move on to filling it in relatively few visits. *The number of visits varies with the condition of the tooth.
Number of visits for an infected canal or retreatment
Where pus has built up at the root tip, or the case is a retreatment, the inside of the canal has to be cleaned and disinfected repeatedly, so more visits are usually needed than for a pulpectomy. At your first visit we will tell you the treatment plan and roughly how many visits to expect, and fit the schedule around your availability.
3 reasons treatment can take a while
- The canal is narrow and complex in shape, so cleaning it takes a number of visits.
- A large lesion at the root tip needs repeated disinfection while we check on recovery.
- For retreatment, removing the earlier filling material, post and core takes time.
The cost of root canal treatment (insurance and self-pay)
So that you are not left uncertain about cost once treatment begins, we explain the basic breakdown of fees first.
Guide cost for insurance-covered root canal treatment
Root canal treatment can be carried out under public health insurance. The insurance fee is set under a nationally standardised fee-point schedule, and varies with the position of the tooth (front tooth, premolar or molar), the number of roots, and what the treatment involves. The cost of the post and core and the crown is calculated separately.
At the examination and diagnosis stage we will explain the likely cost based on the condition of your mouth. Please ask us about anything that is not clear.
Guide cost for self-pay precision root canal treatment
Self-pay precision root canal treatment has fewer restrictions on treatment time and the equipment and materials used — it is treatment outside the insurance system that takes more time to carry out with greater precision. We will explain our specific options and costs at diagnosis, based on the condition of your mouth.
The difference between insurance and self-pay treatment
Insurance-covered treatment gives you standardised care under nationally uniform rules. Self-pay treatment lets you choose from a wider range of equipment, materials and treatment time to achieve more precise care. Which suits you better depends on the condition of the tooth, and we will explain this after diagnosis.
About pain during root canal treatment
How we limit pain during treatment
Because we use anaesthetic, you will feel almost no pain during treatment itself. We use a topical anaesthetic and an electric syringe to keep even the pain of the injection to a minimum.
How long throbbing pain can last after treatment
For a few days after root canal treatment, you may feel a foreign-body sensation or mild pain when chewing. This is a temporary inflammatory reaction to the treatment and usually settles gradually. If the pain is more severe, we will prescribe painkillers — please don’t put up with it, and let us know.
Possible causes if pain continues
If pain continues for a long time, the cause may be a bite that is sitting too high, inflammation still remaining in the canal, or a fine crack in the tooth, among other things. If the pain has not settled after a few days, or is getting worse, please contact us as soon as you can.
For anyone told elsewhere that extraction is needed
Even if pain or swelling has led to advice to “extract” the tooth, please talk to us once before giving up — there may still be a way to save it.
Cases where root canal treatment may still save the tooth
Even with a large lesion at the root tip, if the root itself is still intact there may be a chance of saving the tooth through retreatment or an apicoectomy. Please let us assess your specific situation before deciding anything.
Cases where extraction is needed
Where the root has a large crack, or a great deal of the bone supporting the tooth has been lost, for example, keeping the tooth can itself carry risks, and in these cases we may recommend extraction. Even then, we will explain the options available after extraction in full.
A guide to getting a second opinion
Even if another clinic has diagnosed you as needing extraction, we will examine the tooth and explain whether it can be saved and what the treatment options are. We also see patients for a second opinion — please feel free to contact us at any time.
Preventing recurrence after treatment
Why protecting the tooth with a crown matters
A tooth that has had its nerve removed loses its supply of nutrients and moisture, so it becomes more brittle than a healthy tooth. This makes it important to reinforce it securely with a crown. A high-precision crown not only keeps bacteria from entering through gaps but also plays an important part in preventing recurrence.
Catching recurrence early with regular check-ups
After treatment finishes, it is important to keep having regular check-ups and X-rays to confirm the condition of the root tip and the crown. Catching any sign of recurrence early gives you more options for dealing with it. We also offer professional cleaning carried out by our dental hygienists.
Learn more about preventive dentistryFAQ about root canal treatment
Q1. What is the beeping sound during treatment?
It is the sound of the device that measures the length of the canal (the apex locator) at work. This device measures the distance to the root tip electronically, and the sound itself is neither painful nor a cause for concern.
Q2. What happens if I don’t have root canal treatment?
Tooth decay or infection at the root will not heal on its own — left alone, the infection will simply keep spreading. Even if the pain eases for a while, it is often still progressing underneath, and as time passes the chances of saving the tooth fall and your treatment options narrow. Please talk to us as early as you can, before it comes to extraction.
Q3. What should I do if the temporary filling comes out?
A temporary filling can come out if you bite something hard. If it is left out, bacteria will get into the canal, so please contact us as soon as possible. We will deal with it straight away, without waiting for your next appointment.
Q4. Does pain when chewing after treatment mean it has failed?
A foreign-body sensation or mild pain in the first few days after treatment is mostly a temporary inflammatory reaction from the treatment itself, and does not necessarily mean it has failed. It usually eases gradually, but if the pain gets worse or lasts a long time, adjusting the bite or other treatment may be needed, so please contact us.
Q5. Does root canal treatment on a front tooth affect its appearance?
A tooth that has had its nerve removed can darken over time. For a front tooth, a natural appearance can be restored with a ceramic crown and similar options — please talk to us if you are concerned about how it looks.
If root canal treatment is on your mind, visit a dental clinic 3 minutes from 大手町駅
Does any of this sound familiar?
- Your tooth throbs even when you are doing nothing.
- You’ve been told elsewhere that extraction is your only option.
- Root canal treatment was left unfinished partway through.
- A tooth you’ve had treated still hurts when you chew, or still feels odd.
Book or ask us here
Hamille Tokyo Dental Office is committed to precision root canal treatment that saves as many teeth as possible. Whether you are struggling with pain or have been advised elsewhere to have a tooth extracted, please talk to us first. We are a 3-minute walk from 大手町駅 C2b出口 and a 1-minute walk from 竹橋駅 3b出口, open until 19:00 on weekdays, and we can also see sudden pain and same-day appointments. We put together a treatment plan suited to each patient’s own situation.
