Root canal treatment has a reputation for being painful or harmful, but in most cases, a root canal is not bad for you. It is a dental procedure used to remove infected, inflamed or damaged tissue from inside a tooth.
The aim is to preserve the natural tooth, relieve symptoms, remove the source of infection and prevent the problem from progressing.
Some people worry that root canal treatment may cause cancer, heart disease or other health problems. These concerns are generally based on outdated theories rather than reliable modern evidence. When appropriately diagnosed, carried out and restored, root canal treatment is widely regarded as a safe way to treat infection inside a tooth.
Are Root Canals Bad for You? The Short Answer
No. Root canal treatment is not considered bad for your health when it is clinically necessary and performed correctly.
During treatment, the dentist or endodontist removes damaged or infected pulp from inside the tooth. The root canal system is then cleaned, shaped, disinfected, filled and sealed.
The roots themselves are not removed. The treated tooth remains in the mouth and can continue to function, although it may require a permanent filling, onlay or dental crown afterwards.
Leaving a serious dental infection untreated is generally a greater concern than having appropriate root canal treatment. Infection may cause increasing pain, an abscess, damage to the surrounding bone or significant swelling.
What Is Root Canal Treatment?
Inside every tooth is a space containing dental pulp. The pulp consists of nerves, blood vessels and connective tissue.
The pulp can become inflamed, infected or irreversibly damaged because of:
- Deep tooth decay
- A cracked, chipped or broken tooth
- A large or failing filling
- Repeated dental treatment on the same tooth
- Trauma or injury
- A dental abscess
- Leakage underneath an existing restoration
During root canal treatment, the affected pulp is removed. The dentist then cleans and seals the canal spaces inside the roots to reduce the risk of further infection.
A general dentist may perform the treatment, or a patient may be referred to an endodontist—a dentist with additional expertise in diagnosing and treating problems involving the dental pulp and root canals.
Why Do Root Canals Have a Bad Reputation?
Root canals are strongly associated with toothache, but the pain usually comes from the inflamed or infected tooth rather than the treatment itself.
Before treatment, patients may experience:
- Severe or throbbing toothache
- Pain when biting or chewing
- Lingering sensitivity to hot or cold
- Swelling around the tooth or gum
- A bad taste in the mouth
- A small gum swelling or “gum boil”
- Tenderness around the jaw
Patients often remember the pain that led to the root canal and associate it with the procedure. In reality, treatment is intended to remove the inflamed or infected tissue causing the symptoms.
Patients who feel anxious about dental treatment can discuss their concerns before the appointment. Glow Dental also provides support for nervous dental patients.
Are Root Canals Safe?
For most patients, root canal treatment is considered safe. Dentists use local anaesthetic, dental instruments, disinfecting solutions and sealing materials to treat the canal system and restore the tooth.
As with any dental procedure, root canal treatment is not completely free from risk. Possible complications include:
- Persistent or returning infection
- A canal that is difficult to locate or clean
- Fracture of the tooth
- Damage to an instrument inside a complex canal
- Leakage underneath a filling or crown
- Continued pain or tenderness
- The need for retreatment, surgery or extraction
These possibilities should be considered alongside the risks of leaving an infected tooth untreated or removing a tooth that may otherwise be saved.
Do Root Canals Cause Cancer or Other Diseases?
There is no reliable scientific evidence showing that root canal treatment causes cancer, heart disease or systemic illness.
Claims connecting root-treated teeth with disease elsewhere in the body are commonly linked to an old theory known as focal infection theory. The research behind those claims predates modern understanding of disease, sterilisation, imaging and endodontic treatment.
Modern root canal treatment is designed to remove infected or damaged tissue and seal the inside of the tooth. Patients with concerns should discuss the evidence, their diagnosis and the available alternatives with their dentist or endodontist.
When Is Root Canal Treatment Necessary?
Root canal treatment may be recommended when the dental pulp is irreversibly inflamed, infected or dead and the tooth can still be restored.
Possible reasons include:
- Decay extending into the pulp
- A crack or fracture affecting the inside of the tooth
- A dental abscess associated with the tooth
- Trauma that has damaged the pulp
- Repeated treatment that has irritated or damaged the pulp
- Infection around the end of the root visible on an X-ray
Sometimes the tooth is severely painful. In other cases, the nerve has already died and the tooth may produce few symptoms despite infection being present.
A dentist usually assesses the tooth using the patient’s symptoms, a clinical examination and dental X-rays. Further tests may be used to evaluate the pulp and the tissues around the root.
What Are the Signs That You May Need a Root Canal?
Symptoms that should be assessed include:
- Severe or persistent toothache
- Pain when biting or chewing
- Sensitivity that continues after hot or cold stimulation
- Swelling of the gum, face or jaw
- A recurring gum boil
- A bad taste or discharge around the tooth
- Darkening or discolouration of a tooth
- Tenderness around the root
These symptoms do not automatically mean that root canal treatment is required. Tooth decay, gum problems, cracks, bite issues and other conditions can cause similar symptoms.
Persistent pain or swelling should be assessed through a dental examination.
Does Root Canal Treatment Hurt?
Root canal treatment is normally carried out using local anaesthetic. The tooth and surrounding area should therefore be numb during the procedure.
Patients may notice pressure, vibration or movement, but significant sharp pain is not expected. If discomfort occurs, the dentist can stop, assess the situation and provide additional anaesthetic where appropriate.
A severely inflamed tooth can sometimes be more difficult to numb. Dentists can use additional anaesthetic techniques to make treatment more comfortable.
Which Stage of Root Canal Treatment Is Most Painful?
The most painful stage is often the period before treatment, when the pulp is inflamed or infection is causing pressure in or around the tooth.
After treatment, the tooth and surrounding tissues may feel tender or bruised for a short period, particularly when biting. This should normally improve as the area settles.
Patients should contact their dentist if:
- Pain becomes more severe rather than improving
- Significant swelling develops
- The bite feels high or uneven
- Symptoms return after initially settling
- The temporary filling or restoration becomes loose
What Happens During Root Canal Treatment?
The exact treatment process depends on the tooth, the number and shape of its canals and the extent of infection.
Common stages include:
- Examination and X-rays: The dentist assesses the tooth, surrounding bone and root anatomy.
- Local anaesthetic: The tooth and surrounding area are numbed.
- Isolation: A dental dam may be placed around the tooth to keep the treatment area clean and dry.
- Access: An opening is made in the tooth to reach the pulp chamber and canals.
- Cleaning: Infected, inflamed or dead pulp tissue is removed.
- Shaping and disinfection: The canals are carefully shaped, cleaned and disinfected.
- Filling: The prepared canals are filled and sealed.
- Restoration: The tooth is restored with a filling, onlay or crown where appropriate.
Treatment may be completed during one appointment or over several visits. A temporary filling may be placed between appointments.
Will Root Canal Treatment Remove the Infection?
Root canal treatment aims to remove infected or damaged tissue and reduce microorganisms inside the canal system before the space is filled and sealed.
If infection has affected the tissues or bone around the root, healing may continue after the procedure. Follow-up X-rays may be used to monitor the response over time.
No dental treatment can guarantee success in every case. Persistent or returning infection can occur if:
- A canal is extremely narrow, curved or difficult to locate
- Complex anatomy prevents complete cleaning
- The final restoration leaks
- New decay develops
- The tooth fractures
- The permanent restoration is delayed
If infection remains or returns, possible options include root canal retreatment, endodontic surgery or extraction where the tooth cannot be predictably restored.
Do You Need Antibiotics After a Root Canal?
Antibiotics are not routinely required after root canal treatment.
In many cases, the source of the problem is managed through local dental treatment, such as cleaning the root canals, draining an abscess or removing the affected tooth.
A dentist may prescribe antibiotics where there are signs that an infection is spreading or affecting the patient more generally. These signs may include:
- Facial swelling or cellulitis
- Fever or feeling systemically unwell
- Swollen lymph nodes
- Increasing difficulty opening the mouth
- Other clinical risk factors identified by the dentist
The appropriate medicine depends on the diagnosis, allergies, medical history, other medicines and current prescribing guidance.
Do not take leftover antibiotics or antibiotics prescribed to someone else. Antibiotics alone do not usually remove the source of an infection inside a tooth, so appropriate dental treatment is still required.
How Many Root Canals Does a Tooth Have?
The phrase “how many root canals per tooth” usually refers to the number of canal spaces inside the roots.
As a general guide:
- Front teeth commonly have one canal
- Canine teeth commonly have one canal
- Premolars may have one or more canals
- Molars commonly have several canals
Root canal anatomy varies considerably. Some teeth have additional, narrow, divided or curved canals, which can make treatment more complex.
Can the Same Tooth Have Root Canal Treatment More Than Once?
Yes. If infection remains or returns, it may be possible to perform root canal retreatment.
During retreatment, the dentist or endodontist reopens the tooth, removes the previous root-filling material, cleans the canal system again and reseals it.
Retreatment may be considered where there is:
- A previously missed canal
- Persistent infection around the root
- Leakage underneath a filling or crown
- New decay affecting the tooth
- Complex canal anatomy
Where conventional retreatment is unsuitable, endodontic surgery may be considered. An apicectomy, for example, involves treating infection around the end of the root.
Root Canal Treatment Versus Tooth Extraction
Root canal treatment aims to preserve the natural tooth, while an extraction removes it completely.
Saving a restorable natural tooth may help maintain chewing function, appearance and the position of neighbouring teeth. However, root canal treatment is not appropriate where the tooth cannot be predictably restored.
Extraction may be considered where:
- The tooth has a severe or untreatable crack
- Very little healthy tooth structure remains
- The tooth has inadequate gum or bone support
- The infection cannot be predictably treated
- The tooth cannot support a suitable final restoration
If a tooth is removed, replacement options may include a dental implant, dental bridge or denture.
The most appropriate option depends on the tooth, surrounding tissues, general oral health, cost, treatment preferences and long-term prognosis.
Can a Root Canal Fail?
Yes. Root canal treatment can fail, although many treated teeth remain functional for years.
Possible reasons include:
- A missed or inaccessible canal
- Very narrow or curved anatomy
- Persistent microorganisms inside the canal system
- Leakage underneath the final restoration
- New tooth decay
- A fracture in the tooth or root
- Delayed placement of the permanent restoration
Signs of a possible problem include:
- Returning toothache
- Pain when biting
- Swelling
- A recurring gum boil
- Tenderness around the root
- Changes visible on a follow-up X-ray
Depending on the cause, treatment may involve adjustment of the bite, replacement of a leaking restoration, root canal retreatment, endodontic surgery or extraction.
Does a Root Canal Tooth Need a Crown?
Not every root-treated tooth needs a crown, but some require additional protection after treatment.
A crown or another form of cuspal coverage may be recommended where substantial tooth structure has been lost, particularly on a back tooth exposed to heavier chewing forces.
The appropriate restoration depends on:
- The amount of healthy tooth remaining
- The location of the tooth
- Whether cracks are present
- The size of previous fillings
- The patient’s bite
- Whether an inlay, onlay, filling or crown can provide suitable protection
The final restoration is an important part of treatment because leakage or fracture can affect the long-term outlook for the tooth.
How to Look After a Tooth After Root Canal Treatment
Until the tooth has received its permanent restoration, patients may be advised to avoid biting particularly hard foods on it.
To maintain a root-treated tooth:
- Brush twice daily with fluoride toothpaste
- Clean between the teeth every day
- Attend follow-up appointments
- Have the permanent restoration placed as advised
- Attend regular dental examinations
- Report returning pain, swelling or looseness
- Avoid using the tooth to bite hard objects or open packaging
A root-treated tooth can still develop tooth decay or gum disease. Although the pulp has been removed, the outer tooth structure and surrounding gums still require regular care.
When Should You Seek Urgent Dental Advice?
Contact a dentist urgently if you have:
- Severe or increasing toothache
- Swelling of the face or jaw
- A suspected dental abscess
- A high temperature with dental pain or swelling
- Pus or a persistent bad taste
- Increasing difficulty opening your mouth
Glow Dental provides emergency dental assessments for patients experiencing urgent dental problems.
Call 999 or attend A&E if you have significant swelling and are finding it difficult to breathe, speak or swallow, or if swelling is affecting the eye or eyesight.
Why Choose Glow Dental for Root Canal Treatment?
At Glow Dental, root canal assessment begins with a careful examination of the affected tooth, surrounding gums, bite and dental X-rays.
We explain:
- Why root canal treatment may be recommended
- Whether the tooth appears restorable
- The expected stages of treatment
- Possible alternatives
- The likely final restoration
- The risks of treatment and leaving the tooth untreated
Where the case is particularly complex, referral to an appropriate endodontic clinician may be considered.
Book a Root Canal Assessment at Glow Dental
Persistent toothache, pain when biting, swelling or prolonged sensitivity may indicate a problem affecting the pulp or tissues around a tooth.
Glow Dental provides root canal assessments and restorative dental treatment at our practice on Northcote Road in Battersea, close to Clapham Junction. We welcome patients from Clapham, Wandsworth, Chelsea and surrounding areas of South West London.
During your appointment, we can examine the tooth, take any necessary X-rays and explain whether root canal treatment, another restorative option or extraction may be appropriate.
New patients can find further information on our new patient page.
Book a dental assessment at Glow Dental.
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Glow Dental
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