Front tooth after trauma
A non-vital incisor turns greyish over time — typical after falls or sports injuries, often visible years after the event.
09 — Cosmetic lightening
Internal
bleaching in Kiel.
When a root-treated tooth becomes darker than the teeth beside it. The walking bleach technique lightens it from the inside — safely, with a cervical safety barrier.
What is it?
Lightening
from the inside.
Internal bleaching — also called the walking bleach technique — is the gentle cosmetic lightening of a root-treated tooth that has become discoloured. The bleaching agent is not applied from the outside, but placed inside the pulp chamber.
Why ‘walking'? The dressing ‘walks' inside the tooth — it works between appointments while you carry on with everyday life. Over 1 to 4 sessions the dressing is changed until the desired result is reached.
The decisive safety factor is the cervical barrier: before the bleaching agent is placed, we build up a tight seal at the neck of the tooth — it prevents the external cervical resorption that could occur with older bleaching techniques.
When is it suitable?
Typical
indications.
Internal bleaching is the specific answer to discolouration from inside the tooth — usually in single root-treated teeth.
Old root filling
Classic root filling materials (especially those containing silver) stain the dentine from within — grey discolouration visible years after treatment.
Pulp necrosis
After the pulp dies, blood residues break down inside the tooth — the breakdown products cause a noticeable discolouration.
Important: internal bleaching works only on root-treated teeth. Vital teeth are lightened with external bleaching (e.g. home bleaching with trays or in-office bleaching) — that is a different treatment.
Our approach
Safe and
predictable.
What sets internal bleaching apart from older methods: a safety barrier, microscopic control, gentle materials.
Cervical safety barrier
A layer of glass ionomer cement or composite at the neck of the tooth — it stops the bleaching agent reaching the root filling or the bone. Protection against external resorption.
Cleaning under the microscope
Before the dressing is placed, we remove all discoloured residues from the pulp chamber at 25× magnification — this markedly improves the bleaching result.
Gentle materials
Sodium perborate or low-concentration carbamide peroxide — effective, yet gentle. We avoid highly concentrated hydrogen peroxide solutions.
Staged treatment
We approach the desired shade gradually over 1–4 sessions to avoid over-bleaching — the tooth should look natural.
Procedure
Treatment
step by step.
01
Diagnostics & initial examination
We check the root filling — it must be tight and complete. If the seal is not tight, first a root canal retreatment, then bleaching.
02
Rubber dam & access
A working field with few bacteria. We remove the restorative material and expose the pulp chamber.
03
Cleaning under the microscope
All discoloured residues are removed at 25× magnification. The pulp chamber is rinsed thoroughly.
04
Cervical safety barrier
A layer of glass ionomer cement at the neck of the tooth — protection against external resorption.
05
Placing the bleaching agent
Sodium perborate or carbamide peroxide is placed in the pulp chamber, followed by a tight temporary seal.
06
Changing the dressing
An appointment after 5–10 days to change it — we assess how far the tooth has lightened. 1–4 changes are typical.
07
Definitive restoration
Once the desired result is reached: complete cleaning and a tight composite seal of the access cavity.
08
Check-up after 6 months
We check that the shade is stable and rule out external resorption.
90+%
Success rate
Visible lightening in single root-treated teeth with internal discolouration.
1–4
Sessions
Number of dressing changes — depending on the initial discolouration.
5–10J
Stability
Average durability of the bleaching result — repeatable if needed.
Costs
What does
bleaching cost?
Internal bleaching is a purely cosmetic treatment and is billed privately. Statutory health insurance does not cover it. Privately insured patients often receive partial reimbursement.
Guide prices
- Internal bleaching (1 tooth, 1–2 sessions): approx. €250–450
- With several changes (3–4 sessions): approx. €400–600
- Prior root canal retreatment (if the root filling is not tight): plus the cost of the retreatment
We go through the total cost openly before treatment begins — you know exactly what to expect.
Frequently asked questions
Answers
about bleaching.
The questions our patients ask most often.
When is internal bleaching suitable?
Internal bleaching is the method of choice when a single root-treated tooth becomes darker or greyer than the teeth beside it. It is more effective than external bleaching because it treats the cause of the discolouration inside the tooth.
Is internal bleaching safe?
Used correctly, with a cervical safety barrier (protection against external cervical resorption), internal bleaching is a safe procedure. Prerequisites: a tight root filling and careful technique.
Important: earlier bleaching techniques (1980s, without a protective barrier) could trigger external resorption. Today's methods with a barrier have practically eliminated this risk.
How long does the result last?
Studies show stability over 5–10 years and longer. In some patients the tooth may darken slightly again after some years — repeating the treatment is then usually straightforward.
How many sessions are needed?
As a rule 1 to 4 sessions of 15–30 minutes, with 5–10 days between each. The dressing works continuously inside the tooth during that time.
Does it hurt?
No. The tooth has been root-treated, so the nerve is no longer there. The treatment is pain-free and no anaesthesia is needed.
Does the root filling have to be redone?
Only if it is not tight. A tight root filling is a prerequisite for safe bleaching — if it is not, we first carry out a root canal retreatment.
What does the treatment cost?
Internal bleaching usually costs 250–600 euros for one tooth, depending on how often the dressing is changed. We provide a written cost estimate before treatment begins.
How does this differ from ordinary bleaching?
External bleaching (e.g. home bleaching with trays or in-office bleaching) is applied to all teeth from the outside — it suits vital teeth with even discolouration. Internal bleaching works only on the single discoloured tooth from the inside, in a targeted and effective way.
More treatments
Related
treatments.
Internal bleaching is often part of a larger treatment plan.
Prerequisite
root canal retreatment
If the root filling is not tight — renew it before bleaching.
Find out more PrimaryRoot canal treatment
If the pulp is non-vital — treat the root before bleaching.
Find out more RiskRoot resorption
Practically ruled out with a cervical barrier — but follow-up matters.
Find out more Vitality preservationApexogenesis
When a young tooth is still vital after trauma — before bleaching becomes necessary.
Find out moreBook
Tooth gone grey?
We can lighten it.
Internal bleaching can be booked directly. Safe walking bleach technique with cervical protection.