What Causes a Root Canal Infection and How Is It Treated?

There are many reasons a tooth can hurt. But if your tooth hurts deep inside, keeps hurting, or gets worse when you chew, it could be a sign of trouble inside the tooth. Inside the hard outer layers is the dental pulp containing the nerves and blood vessels. If decay, a crack, a broken filling or an injury lets bacteria into this area, the pulp can get infected. A root canal infection may not cause the same symptoms in everyone. For some it might be a sharp pain, but others will first notice a swelling around the tooth or a small lump on the gum. Root Canal Treatment means removing the infected tissue, cleaning the inside of the tooth and sealing it so bacteria cannot get back inside easily.

What Causes a Root Canal Infection and How Is It Treated? Main Causes and Dental Care

Most infections start when bacteria find a way into the centre of the tooth. Deep decay is a common reason. A cavity that is left untreated can slowly move through the enamel and dentin until it reaches the pulp.

A tooth may also become infected after an accident. Even a small crack can give bacteria a path inside. Old or loose fillings can cause a similar problem if a gap forms around them.

An infected root canal can sometimes occur in a tooth that was treated before. This does not always mean the earlier treatment was poor. Teeth can have very thin, curved, or extra canals that are difficult to find.

Common reasons include:

• Deep tooth decay
• A cracked or broken tooth
• An old filling that no longer seals well
• Repeated dental work on the same tooth
• Injury to the tooth
• New decay around a crown or filling
• A canal that was difficult to reach

The sooner the cause is found, the better the chance of keeping the natural tooth.

Signs That Should Not Be Ignored

Tooth pain is one of the most common signs, but it is not the only one. Pain may appear while biting, chewing, or touching the tooth. Some people feel a dull ache that comes and goes.

You may also notice:

• Swelling around the gum
• Sensitivity to hot or cold
• A bad taste in the mouth
• Pus near the tooth
• Tender gums
• A small pimple-like bump on the gum
• Darkening of the tooth

The symptoms of jaw infection after root canal treatment may include increasing pain, swelling, tenderness around the jaw, or facial swelling. Mild soreness can happen after dental work, but pain that keeps getting worse needs a dental check.

An infected root canal front tooth may show fewer chewing symptoms than a back tooth. Instead, the patient may notice gum swelling, colour change, tenderness above the tooth, or a recurring gum boil.

How the Dentist Finds the Problem

The dentist will usually begin by asking where the pain is, when it started, and whether the tooth has been treated before. The tooth, gums, and bite are then checked.

Dental imaging can help show what is going on under the gum line. An OPG shows the teeth and jaws in greater detail. In some cases, CBCT may be advised because it provides a three-dimensional view of the tooth, roots, and nearby bone.

A Dental Microscope can also be useful when the dentist needs a closer look at very small canal openings or areas that are hard to see clearly.

These checks help the dentist decide whether the tooth needs first-time treatment, retreatment, or another type of care.

Root Canal Process in Simple Steps

The root canal process is carried out to clean the infected space inside the tooth while keeping the tooth itself.

The usual steps are:

The dentist examines the tooth and takes the required images.

• Local anaesthetic is given to numb the area.
• A small opening is made in the tooth.
• Damaged or infected pulp is removed.
• The canals are cleaned and shaped.
• The inside of the tooth is disinfected.
• The canals are filled and sealed.
• A filling or crown is placed when required.

A molar root canal may take more time because molars usually have more canals than front teeth. Their roots may also have bends or narrow spaces.

If an earlier treatment has become infected, the dentist may remove the old material, clean the canals again, and reseal the tooth.

How Long Does a Root Canal Take?

Many patients ask how long does a root canal take before booking treatment. There is no fixed time that suits every tooth.

A front tooth often has a simpler canal system, while a molar can have several canals. Infection level, root shape, old dental work, and retreatment can all affect the appointment length.

So, if you are wondering how long does root canal take or how long is a root canal, the dentist can usually give a better estimate after looking at the tooth and dental images.

Some teeth can be treated in one visit. Others may need another appointment.

What Happens After the Canal Is Cleaned?

Once the inside of the tooth has been cleaned and sealed, the outer part still needs protection.

A Dental Fillings may be enough for some teeth. A tooth that has lost more structure may need Crowns/Bridges work to help protect it during biting and chewing.

If a crown or another restoration is planned, a 3D Intra Oral Scanner may be used to take a digital impression.

It is important not to delay the final restoration for too long. A damaged or leaking filling can allow bacteria to enter again.

When Should You Book a Dental Visit?

Do not wait if pain keeps returning, swelling develops, pus appears near the gum, or a treated tooth becomes painful again. Fever, facial swelling, or trouble swallowing needs quick medical or dental attention.

A dental check can show whether the problem comes from the pulp, the surrounding gum, the jaw, or another nearby tooth.

If you are suffering from ongoing tooth pain or notice any signs of infection, Dr Rashida Juzar Ali and the team at Le Denté will be able to examine the area and discuss the next step based on the condition of the tooth.

Frequently Asked Questions

Can a root canal become infected again?

Yes. New decay, cracks, leaking fillings, or bacteria inside a difficult canal can cause another infection.

Is pain normal after treatment?

Mild soreness can happen for a short time. Pain that becomes stronger or lasts should be checked.

Can infection spread to the jaw?

Yes. An untreated dental infection can move into the tissues around the tooth and jaw.

Does every treated tooth need a crown?

No. It depends on the tooth, its location, and how much healthy structure remains.

Can an infected tooth be treated again?

In many cases, yes. The dentist may recommend root canal retreatment if the tooth can still be saved.