How to Save Your Tooth and Prevent Future Infection

written by Longwood Dental staff, reviewed by Dr. Kelly Wang, MMSc., BDent.

Tooth pain can be exhausting, stressful, and sometimes frightening. Many patients delay treatment because they hope the pain will go away on its own — or because they are worried about needing a “root canal.”

The good news is that modern endodontic treatment is far gentler, more precise, and more comfortable than many people imagine.

If you have persistent tooth pain, sensitivity, swelling, or a previously treated root canal tooth that feels “different,” this article will help you understand:

• What root canal treatment actually is

• Common symptoms of tooth nerve infection

• Signs an old root canal may need retreatment

• What “re-endo” or endodontic retreatment means

• Why regular follow-up checks are important

• When to seek treatment early before the problem worsens

At Longwood Dental Taipei, our goal is not just to stop the pain temporarily — but to carefully diagnose the cause, preserve your natural tooth whenever possible, and help you feel calm, informed, and cared for throughout the process by our English-speaking endodontist (dentist specializing in root canal treatments). Many patients also visit Longwood Dental Taipei for a second opinion regarding root canal treatment, cracked teeth, or previously treated teeth that continue to feel uncomfortable. Patients looking for an English-speaking endodontist in Taipei often choose Longwood Dental for clear communication, careful diagnosis, and comprehensive specialty care.

If you are experiencing tooth pain, swelling, or a dental abscess, prompt evaluation and treatment may help prevent worsening infection and improve the chances of saving the tooth.

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What Is Endodontic Treatment (“Root Canal Treatment”)?

Inside every tooth is a soft tissue called the dental pulp, which contains:

• Nerves

• Blood vessels

• Connective tissue

When bacteria enter the inside of the tooth due to:

• Deep cavities

• Cracks

• Trauma

• Old leaking fillings

• Large restorations

• Gum disease

…the pulp can become inflamed or infected.

This often leads to:

• Tooth pain

• Pressure sensitivity

• Swelling

• Infection

• Abscess formation

Endodontic treatment (commonly called a “root canal”) removes the infected tissue inside the tooth, disinfects the root canal system, and seals the tooth to help prevent reinfection.

The goal is to save your natural tooth whenever possible.

Common Symptoms That May Indicate You Need a Root Canal

Not all infected teeth hurt constantly.Some infections progress quietly for months or even years. Common symptoms include:

Persistent Tooth Pain

• Spontaneous pain

• Throbbing pain

• Deep aching pain

• Pain that wakes you up at night

• Pain when chewing

• Pain that does not respond to over the counter painkillers

Sensitivity to Hot or Cold

Especially if:

• The pain lingers after the stimulus is removed

• Hot drinks trigger pain

• Cold sensitivity becomes sharp or prolonged

Pain When Biting

You may feel:

• Pressure pain

• Sharp discomfort when chewing

• Sensation that the tooth feels “high”

Gum Swelling or Pimple Near the Tooth

This may indicate:

• Infection draining through the gums

• A dental abscess

Tooth Darkening or Discoloration

A tooth that becomes gray or dark may indicate nerve damage or a dying tooth pulp.

Swelling of the Face or Jaw

This can indicate a spreading infection and should be evaluated promptly.

A Tooth That Feels “Different”

Some patients describe:

• Pressure sensation

• Mild discomfort

• Occasional strange taste

• Intermittent swelling

Even without severe pain, these symptoms can still indicate chronic infection.

Can a Tooth Infection Go Away on Its Own?

Unfortunately, no. Pain may temporarily decrease if the nerve inside the tooth dies, but the bacteria and infection often remain.

Without treatment, infection can:

• Spread into the jawbone

• Cause swelling or abscesses

• Lead to bone loss

• Damage neighboring teeth

• Eventually require tooth extraction

Early treatment is usually:

• Simpler

• Less invasive

• More comfortable

• More predictable

• More affordable

What Happens During Root Canal Treatment?

Modern root canal treatment is focused on precision, disinfection, and patient comfort.

At Longwood Dental Taipei, treatment may include:

• Careful diagnosis and digital X-rays

• Local anesthesia for comfort

• Isolation of the tooth with rubber dam

• Cleaning and shaping of the root canals

• Disinfection to reduce bacteria

• Sealing the canals

• Placement of a post when needed and a definitive filling or crown to support the tooth structure and restore chewing function. 

Many patients are surprised that modern root canal treatment often feels similar to receiving a filling.

What Is Endodontic Retreatment (“Re-Endo” or “Endo Retreat”)?

Sometimes, a tooth that previously received root canal treatment can become reinfected.

This is called:

• Endodontic retreatment

• Root canal retreatment

• Re-endo

• Endo retreat

This does not necessarily mean the previous dentist or endodontist “did something wrong.”

Root canal systems can be extremely complex, and reinfection may occur years later due to:

• Hidden anatomy

• Residual bacteria

• New decay

• Cracks

• Leaking crowns or fillings

• Breakdown of old restorations

Common Signs You May Need Root Canal Retreatment

A Previously Treated Tooth Starts Hurting Again

(Even mild discomfort may be significant.)

Swelling or Gum Pimple Near an Old Root Canal Tooth

Pain When Chewing

Persistent Bad Taste or Drainage

Darkening of the Tooth

X-Ray Shows Infection Around the Root

A lot of  patients have no symptoms at all and only discover problems during routine dental examinations. This is very common.

If You’ve Had a Root Canal Before:

When Was the Last Time You Had It Checked?

Many patients assume that once a root canal is completed, the tooth never needs follow-up again.

However, regular examinations are important because:

• Small reinfections may not cause immediate pain

• Old crowns or fillings can begin to leak

• Residual bacteria can slowly reinfect the tooth

• Early detection can help save the tooth before major damage occurs

At Longwood Dental Taipei, we often discover silent infections during routine examinations — even in teeth treated many years ago.

Catching problems early can:

• Prevent severe pain

• Reduce treatment complexity

• Improve long-term prognosis

• Help to avoid extraction

Why Some Root Canal Treatments Fail

Root canal systems can be highly complex and microscopic.

Reasons for reinfection may include:

• Narrow or curved canals

• Additional hidden canals

• Old technology used during earlier treatment

• Delayed crown placement

• Cracked teeth

• New bacterial leakage over time

This is why careful diagnosis, proper sealing, and long-term monitoring are important.

Is Root Canal Treatment Painful?

This is one of the most common patient concerns.

Modern endodontic treatment is designed to RELIEVE pain — not create it.

With modern anesthesia and techniques, many patients describe the experience as:

• Much easier than expected

• Similar to receiving a filling

• Less uncomfortable than living with the infection itself

At Longwood Dental Taipei, we understand dental anxiety and aim to create a calm, supportive, and gentle treatment experience.

Can a Root Canal Save My Tooth?

In many cases, yes.

Saving your natural tooth is often preferable because it helps to maintain:

• Natural chewing function

• Jawbone support

• Bite balance

• Long-term oral health

However, every case is unique, and sometimes severely damaged teeth may not be savable.

A careful examination and X-rays are necessary to determine the best treatment options.

Why Early Evaluation Matters

Many patients wait until pain becomes unbearable before seeking care.

Unfortunately, delaying treatment can sometimes lead to:

• More severe infection

• Swelling

• Cracks

• Tooth fractures

• Bone loss

• Higher risk of extraction

If something feels unusual, it is often better to evaluate it early.

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Why Patients Choose Longwood Dental Taipei for Root Canal Treatment

Experienced Endodontic Care

We have on-site English-speaking endodontists (root canal specialists)  to provide careful diagnosis and modern endodontic treatment and equipment focused on preserving natural teeth whenever possible.

Comfortable, Calm Environment

We understand that many patients feel anxious about tooth pain and root canals.Our goal is to help you feel informed, supported, and comfortable throughout the process.

English-Speaking Dental Clinic in Taipei

Longwood Dental is experienced in treating both local and international patients and provides clear English communication for patients who prefer English-speaking dental care in Taipei.

Comprehensive Evaluation

We evaluate not only the painful tooth, but also:

• Bite forces

• Cracks

• Existing restorations

• Gum condition

• Long-term prognosis

Focus on Long-Term Tooth Preservation

Our goal is not simply to “treat pain,” but to help patients maintain healthy, functional teeth for as long as possible.

Common Questions About Root Canal Treatment

How long does a root canal take?

Some treatments can be completed in one visit, while more complex cases may require multiple appointments.

Will I need a crown afterward?

Many root canal treated teeth benefit from crowns for long-term protection, especially back teeth.

Can antibiotics cure the infection instead?

Antibiotics alone usually cannot fully eliminate infection inside the tooth.

Is retreatment always possible?

Not every tooth can be retreated successfully, but many previously treated teeth can still be saved.

How do I know if my old root canal is failing?

Sometimes there are symptoms, but sometimes problems are only visible on X-rays. Regular dental examinations are important.

Don’t Ignore Tooth Pain

Tooth pain is your body’s way of telling you something may be wrong.

Whether you have:

• New tooth pain

• Sensitivity

• Swelling

• Pain when chewing

• An old root canal tooth that feels “off”

…early evaluation can often make treatment simpler and help preserve your natural tooth.

If you are experiencing symptoms or would like to evaluate a previously treated root canal tooth, Longwood Dental Taipei is here to help.

Looking for Root Canal Treatment or Endodontic Retreatment in Taipei?

At Longwood Dental Taipei, we understand that patients seeking root canal treatment are often dealing with tooth pain, swelling, sensitivity, dental anxiety, or concerns about saving a natural tooth. Our goal is to provide careful, modern, and patient-focused endodontic care in a calm and supportive environment with an experienced English-speaking endodontist in Taipei.

Longwood Dental Taipei provides:

• Root canal treatment

• Endodontic retreatment (“re-endo” or root canal retreatment)

• Evaluation of painful teeth

• Assessment of previously treated root canal teeth

• Diagnosis of cracked teeth and dental infections

• English-speaking endodontic and dental care in Taipei

With sufficient time for specialist care and treatment, patients can often receive timely diagnosis and effective treatment for tooth pain, failed root canals, swelling, infection, pain when chewing, and sensitivity to hot or cold. Early evaluation can help reduce complications and improve the chances of preserving your natural tooth long-term.

Patients choose Longwood Dental Taipei for:

• Experienced endodontic and root canal care

• Gentle, careful, and patient-centered treatment

• Comprehensive evaluation and modern diagnostic technology

• Clear English communication for local and international patients

• Convenient access for patients from Dazhi, Neihu, Tianmu, Shilin, Zhongshan, Songshan, and Xinyi

If you are unsure whether your symptoms are serious, scheduling an examination early can help provide clarity, peace of mind, and appropriate treatment options before the problem worsens.

Our English speaking endodontists and dentists at Longwood Dental Clinic Taipei is here to help guide you calmly and honestly through your options. You can book your appointment online or contact our team directly with any questions.

At Longwood Dental, dentistry is not about rushing through procedures. It is about listening carefully, explaining clearly, and caring thoughtfully—every step of the way.