Do I need a root canal or a filling? How to tell when it’s time to see a dentist

Tooth pain, sensitivity, or a strange sensation when biting can be signs that something’s not quite right. But how do you know whether it’s something simple, like a cavity, or something more serious, like an infection deep inside the tooth? One of the most common questions we hear from patients is: do I need a root canal or a filling?

At Rumney Endodontics in Cardiff, we specialise in helping patients understand exactly what’s going on with their teeth—and what the best treatment is. In this blog, we’ll guide you through how to tell the difference, what both treatments involve, and when it’s time to seek expert advice.

What Is A Filling?

A filling is a routine treatment used to restore a tooth that has been damaged by decay. When plaque builds up on the teeth and isn’t removed through brushing or hygiene treatment, it can lead to a cavity forming in the enamel. Your dentist will remove the decay and fill the space with a durable material—usually composite resin—to protect the tooth and restore its function.

You might need a filling if:

• You have a small to moderate cavity

• You experience mild discomfort or sensitivity to sweet foods or cold drinks

• You can feel a rough patch, hole or pit on your tooth

• A piece of your old filling has chipped or fallen out

What Is A Root Canal?

A root canal is a more advanced treatment that focuses on saving a tooth that’s become infected or severely inflamed on the inside. The procedure removes the damaged or infected pulp tissue from the tooth’s root canals, cleans and disinfects the area, and seals it to prevent reinfection.

You may need a root canal if:

• You have ongoing or severe tooth pain (especially when biting or chewing)

• Your tooth is sensitive to heat or pressure

• There’s swelling in the gum around a tooth

• You’ve had trauma or injury to the tooth

• You notice darkening or discolouration of the tooth

How To Tell Which One You Might Need

It’s not always obvious whether you need a filling or root canal—both can present with pain or sensitivity. But generally, the key difference is that a filling treats damage on the outside of the tooth, while a root canal treats infection or inflammation on the inside.

If left untreated, a small cavity may grow and eventually reach the tooth’s nerve, leading to infection—and at that stage, only a root canal can save it. That’s why regular check-ups are so important.

At Rumney Endodontics, our root canal dentists in Cardiff use advanced diagnostics like digital X-rays and CBCT 3D imaging to determine exactly what’s going on inside the tooth. We can pinpoint the source of pain and recommend the right treatment—whether that’s a simple filling or expert endodontic care.

Why Root Canal Treatment Shouldn’t Be Feared

The idea of a root canal often makes people anxious—but the reality is very different from the horror stories. At our Cardiff clinic, we carry out root canal treatment in a calm, comfortable environment using high-powered microscopes and the latest rotary tools for precision and comfort.

We’ll fully numb the tooth and surrounding area, talk you through the steps, and ensure you feel in control at all times. Most patients are surprised by how straightforward the process is—and how much better they feel afterwards.

What Happens If You Delay Treatment?

Delaying treatment for tooth pain or cavities can lead to:

• Worsening infection

• Tooth abscesses

• Spread of bacteria to other parts of the body

• Tooth loss

Early intervention is key. The sooner you seek help, the more likely we can resolve the issue with a simpler, less invasive procedure—and save your natural tooth in the process.

What Makes Rumney Endodontics Different?

As a dedicated centre for endodontics and general dentistry in Cardiff, we offer:

• GDC-registered endodontic specialists

• Emergency dentist services in Cardiff

• Advanced root canal retreatment for previously failed cases

• Patient-focused care with clear, honest advice

Whether you’re Googling “do I need a root canal or a filling” or searching for a “root canal dentist near me,” our team can help you take the next step with confidence.

Need Help? Contact Us Today

If you’re experiencing tooth pain or sensitivity and are unsure what treatment you need, get in touch with Rumney Endodontics. We’re happy to offer a consultation, second opinion, or emergency appointment if needed.

Book online now.