Internal Teeth Bleaching

Lightens the stain from inside the tooth, where it sits.

This technique is minimally invasive and preserves your natural tooth structure, unlike more aggressive options like veneers or crowns.

It is the only method that can remove deep internal stains from blood byproducts or old filling materials, which external whitening strips cannot reach.

Several factors can cause a tooth to darken internally after endodontic treatment:

This is the most common cause. When the pulp tissue inside the tooth degenerates (either before or during the root canal), haemoglobin from the blood breaks down. These dark-coloured byproducts can penetrate the microscopic tubes in your tooth’s structure (dentin tubules), creating a deep grey or brown internal stain that external whitening products cannot reach.

Some older root canal sealing materials, particularly those used 10 or more years ago, contained silver ions. Over time, these materials can migrate into the dentin, causing a gradual darkening or staining.

The removal of the pulp and blood supply causes subtle dehydration and structural changes within the dentin. This can reduce the tooth’s natural light transmission, making it appear duller or more opaque than the surrounding “living” teeth.

Not all teeth have the same risk of discolouration:

• High-Risk Teeth
  Front teeth (incisors and canines) are the most likely to show noticeable discolouration. Teeth that require a root canal due to trauma are also at higher risk because of extensive blood breakdown.
• Lower-Risk Teeth
  Back teeth (molars and premolars) can also discolour, but it is far less noticeable as they are not prominent in your smile.

Darkening isn’t always immediate. It can follow a few different patterns:

• Immediate (within weeks)
  Some staining may be visible quickly due to blood breakdown products.
• Gradual (6-24 months)
  This is the most common pattern. You may notice a progressive, slow darkening over time.
• Delayed (years later)
  Discolouration appearing many years after treatment is often linked to the migration of sealer materials.

Understanding the step-by-step procedure can help demystify the treatment.

We make a small opening in the back of your tooth. This is often the same access point that was used during your original root canal treatment.

A bleaching agent is carefully placed inside the tooth’s chamber. This gel makes direct contact with the stained dentin from the inside.

We seal the tooth with a secure temporary filling. This traps the bleaching agent safely inside.

You leave our practice and go about your normal life for 3-7 days. This is why it’s called “walking bleach”. You walk around while the gel works internally.

You return to our practice. We remove the gel and assess the new shade. This process is typically repeated 2-4 times until we achieve the desired level of whitening.

Once you are happy with the new shade, we permanently seal the tooth with a tooth-coloured composite resin that matches your natural smile.

Many patients ask why they can’t just use whitening strips. The answer is simple: the stain is in the wrong place.

• External Whitening (Strips, Trays)
  These products are designed to only whiten the outer enamel surface. They cannot penetrate deep enough to reach the internal dentin staining caused by a root canal. In fact, they can sometimes make the problem look worse by whitening the adjacent teeth, making the dark tooth stand out even more.
• Internal Bleaching
  This technique treats the stain at its source, inside the tooth. The bleaching agent is placed in direct contact with the stained dentin, which is why it works where strips cannot.

Internal bleaching is a very safe procedure when performed by an experienced dental professional. It does not damage your tooth structure or affect the success of your original root canal treatment.

The potential side effects are minimal:

• Temporary Sensitivity
  Some patients experience mild sensitivity, which typically resolves within a week.
• External Root Resorption
  This is a rare complication, and we take steps to reduce the risk.

Your journey begins with a thorough evaluation to confirm that internal bleaching is the right solution for you.

• We perform a clinical examination of the discoloured tooth.
• An X-ray is taken to verify that your original root canal treatment is intact and healthy.
• We use a professional shade guide to document your tooth’s current colour.
• We discuss a realistic outcome and show you the expected shade improvement.
• You receive a detailed treatment plan and a clear cost estimate.

We start by making a small access opening in the back of the tooth. A protective barrier is placed over your root canal filling to keep it safe. We then place the bleaching gel inside the chamber and seal the tooth with a temporary filling. You can then leave and go about your normal day while the gel works.

You will return every 3-7 days. At each visit, we remove the temporary filling, clean out the old gel, and assess the new shade. We then place fresh bleaching gel and reseal the tooth. Most patients require 2-4 of these renewal appointments to reach their optimal shade.

Once you are happy with the colour, we perform the final step. We thoroughly clean the chamber and place a permanent, tooth-coloured composite resin filling to seal the tooth. This final restoration is colour-matched to your newly whitened tooth.

• Total Duration
  3-6 weeks from start to finish.
• Total Appointments
  4-6 visits (including consultation and final restoration).
• Total Chair Time
  Less than 3 hours in total.

Your likely results can be predicted by assessing a few factors:

• Discolouration that is less than 3 years old.
• Staining caused by blood breakdown products (this responds best).
• Front teeth (which allow for easier bleaching penetration).
• Younger patients (more porous dentin structure).

• Staining that is more than 10 years old.
• Darkening caused by metal-based root canal sealers.
• Tetracycline-stained teeth (systemic staining, not RCT-related).
• Severe internal resorption.

Results are usually long lasting, though some gradual darkening can occur over the years. If it does, the procedure can be repeated.

• Sensitivity
  Some patients experience temporary tooth sensitivity. If this occurs, avoid very hot or cold foods and drinks for a few days. Using a desensitising toothpaste can also help.
• Shade Settling
  Your tooth may appear slightly “over-whitened” immediately after the final treatment. This is normal and the colour will settle into its natural, stable shade within one to two weeks as the tooth rehydrates.
• Hygiene
  You can resume your normal oral hygiene routine immediately, including brushing and flossing.

• Oral Hygiene
  Maintain excellent care by brushing twice daily and flossing daily.

• Check-ups
  Keep up your regular check-ups with your general dentist so the tooth and restoration can be monitored.

• Protection
  Avoid trauma to the tooth (e.g., wear a mouthguard for contact sports) and do not smoke, as tobacco can cause new staining.

• Re-Treatment
  
  If you notice gradual darkening again after 5-10 years, the procedure can be safely repeated to restore the bright shade.

While complications are rare, please contact us if you experience any of the following:

• Severe sensitivity that lasts longer than two weeks.
• Gum swelling near the bleached tooth.
• Your tooth becoming loose.
• A new pinkish discolouration appearing on the tooth.

Root canal treatment removes infected or damaged pulp to save your natural tooth.

A darkened front tooth treated with root canal treatment and internal bleaching.

A cracked or broken tooth can cause more than discomfort. It can affect how you eat, sleep and live day to day. Left untreated, a crack can deepen and lead to infection, swelling, and even tooth loss.