Lightening a single dark tooth from the inside, where ordinary whitening cannot reach.
Reviewed by Dr Raul Costa
Published August 2021
Last reviewed September 2025
Examples of our work
Internal bleaching cases showing single dark teeth lightened from the inside, without crowns or veneers.
Before
After
Case study
Internal Teeth Whitening
Dr Raul CostaRestorative and Aesthetic Dentistry
Before
After
Case study
Internal Teeth Whitening
Dr Raul CostaRestorative and Aesthetic Dentistry
Before
After
Case study
Internal Teeth Whitening
Dr Raul CostaRestorative and Aesthetic Dentistry
Before
After
Case study
Internal Teeth Whitening
Dr Raul CostaRestorative and Aesthetic Dentistry
Before
After
Case study
Internal Teeth Whitening
Prof Dr Christian MehlSpecialist in Prosthodontics
Before
After
Case study
Internal whitening of an upper jaw front tooth
Prof Dr Christian MehlSpecialist in Prosthodontics
Internal bleaching lightens a tooth from the inside. Rather than applying gel to the outside of the enamel, the bleaching agent is placed within the tooth itself, in the space left after root canal treatment, and left to work from the centre outwards.
It exists because ordinary whitening cannot fix the problem it solves. When a single tooth darkens after root canal treatment or trauma, the discolouration comes from inside the tooth, not from surface staining. Whitening the outside of that tooth does very little, and whitening the whole arch simply makes the dark tooth stand out more clearly against its brighter neighbours.
Surface staining from tea, coffee, red wine and tobacco sits on the enamel and affects all your teeth roughly equally. That responds to conventional whitening. A single dark tooth is a different problem entirely. It usually follows root canal treatment, where the removal of the pulp changes the tooth from the inside, or trauma, where bleeding within the tooth leaves pigment behind. Old restorative materials can also darken a tooth over years. In every case the discolouration is intrinsic, which is why it needs to be treated from within.
There are three realistic routes, and they differ enormously in how much tooth they cost you.
Internal bleaching treats the discolouration at its source. Nothing is drilled away, nothing healthy is removed, and if it works you keep your own tooth looking like your own tooth. It is by far the most conservative option and by far the cheapest.
A veneer covers the front of the tooth. It works, but it requires enamel to be removed permanently, and a dark tooth underneath can still show through a thin porcelain facing unless the veneer is made opaque, which affects how natural it looks.
A crown covers the tooth entirely. It reliably masks the colour but costs the most tooth structure of all, and a root-treated tooth is already weaker than a healthy one.
Our position is straightforward: try the conservative option first. If internal bleaching gives you the result, you have saved your tooth, your money and your time. If it does not, the other options are still open. That order does not work in reverse.
The tooth must already have had root canal treatment, and that treatment must be sound, which we check with an X-ray before starting. A small access opening is made at the back of the tooth, so nothing is touched on the visible surface. The root filling is sealed off to protect it, the bleaching agent is placed inside the tooth, and a temporary seal is placed on top.
The agent works over several days, and you return for it to be assessed and refreshed. Most cases take around three sessions, which is why the fee covers three. Each appointment takes roughly 90 minutes. Once the shade is right, the access cavity is filled permanently with composite matched to the tooth, and you are done. There is no recovery time at any stage.
Three things matter. The root canal treatment must be sound, since bleaching a tooth with an underlying infection is both futile and unwise. The tooth must be structurally sound enough to be worth saving in this form rather than crowned. And your expectations need to be calibrated, which is why we record the starting shade properly and assess against it rather than relying on memory. Not every tooth lightens to a perfect match, and we would rather tell you that at the start.
The tooth may relapse slightly over the years, and it can be re-treated if it does. Because the shade change is intrinsic, it is generally stable, and it does not need the ongoing maintenance that surface whitening does. Keep up your normal hygiene routine and check-ups, and be aware that the composite sealing the access cavity behaves like any other white filling: it can stain over time and can be polished or replaced.
One point worth planning around: if you intend to whiten your other teeth as well, tell us at the start, so we can sequence the two treatments and match the final shades to each other rather than chasing a moving target.
Our dentists
Meet the team who will look after you.
Restorative and Aesthetic Dentistry
Raul focuses on the aesthetics of implant restorations, designing crowns and bridges that blend seamlessly with your natural smile. He takes time to understand exactly what each patient wants from treatment, then uses smile design and careful shade matching to deliver results that look entirely natural and feel like your own teeth, never like dental work.
Specialist in Prosthodontics
Christian leads our most complex implant and full mouth rehabilitation cases, combining surgical precision with a calm, reassuring manner that puts even the most anxious patients at ease. With decades of experience and an academic background in prosthodontics, he is regularly referred the cases other clinics turn away, and he plans every treatment digitally so there are no surprises along the way.
Dentist
Tami is an award-winning dentist who excels in oral surgery, cosmetic dentistry and Invisalign. Meticulous and compassionate, she quickly puts patients at ease and takes pride in helping them achieve their goals.
Real Google reviews from patients treated at the clinic.
Why choose us
Costs
The fee covers three sessions. Your full written cost is confirmed at consultation.
New patient consultation £240. Your dentist will confirm the exact cost after your consultation.
Find us
38 Queen Anne Street, Marylebone, London W1G 8HZ. A short walk from Bond Street and Oxford Circus.
Book a consultation and we will check the root treatment and tell you honestly what internal bleaching can achieve.
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