Inside the tooth: the space this is all about
Under the hard outer layers of enamel and dentine, every tooth contains a soft core: the pulp, made up of nerve fibres, blood vessels and connective tissue. It fills a chamber in the crown of the tooth and continues down through one, two, three or four canals to the tip of each root, where the vessels and nerves connect with the rest of the body.
That system is far less tidy than the textbook picture. Canals curve, split and rejoin. Side branches leave the main canal near the tip. In many upper molars a second canal hides inside the mesiobuccal root, tucked under a ridge of dentine. Canals also narrow over a lifetime: the tooth lays down new dentine in response to decay, deep fillings or an old knock, and by middle age a canal that was once easy to enter can be a barely visible thread.
Endodontics deals with exactly this space. Once bacteria reach it, the body cannot clear the infection on its own — there is no meaningful blood supply left inside an inflamed or dead pulp for the immune system or for antibiotics to work through. The tissue has to be removed mechanically, the space disinfected and then sealed.
Why a tooth ends up needing this
Deep decay is the commonest route. Bacteria work through enamel and dentine until they reach the pulp.
A crack or a fracture lets bacteria in through a gap far too fine to see without magnification.
Repeated dental work — a large filling replaced twice, a crown preparation, years of small insults — can eventually exhaust the pulp’s capacity to recover.
Trauma. A blow to a front tooth can kill the pulp without breaking anything visible. The tooth may darken years later, or a shadow may appear at the root tip on a routine X-ray.
Advanced gum disease occasionally lets bacteria reach the root tip from the outside, along the root surface.
The result is either an acute pulpitis — the classic throbbing that intensifies at night — or, less dramatically, a pulp that dies quietly and produces a chronic inflammation in the bone around the root tip, found by chance on an X-ray. Pain is a poor guide to how much is wrong.
What actually happens, step by step
No two teeth behave identically, but the sequence below is the one an endodontic treatment follows in our practice, and it is summarised alongside the equipment used on our Root canal treatment (endodontics) – service page (EN).
Before anything is touched
Examination, cold and pressure testing, and an X-ray. Where the flat image leaves a real question open — hidden anatomy, a suspected fracture, a previous treatment that failed — a 3D X-ray (DVT) shows the tooth from every angle. In our practice a DVT costs 178 €, and we order one when it will change the plan, not as routine. Scan data can additionally be reviewed with AI support, which flags findings for the dentist to confirm; the assessment always remains the dentist’s own.
Anaesthetic and isolation
Local anaesthetic (Betäubung) first. An acutely inflamed molar sometimes needs a supplementary injection directly into the ligament around the tooth, because inflamed tissue resists numbing. Then the tooth is isolated with a rubber dam (Kofferdam) — a thin sheet clamped over the tooth. It keeps saliva and its bacteria out of the canal system, keeps the rinsing solutions away from the rest of your mouth, and secures small instruments. Isolation is not a comfort feature; it is one of the conditions under which the treatment can be expected to work.
Opening the tooth
An access cavity is cut through the crown into the pulp chamber. The art here is restraint: enough opening to see and reach the canals, as little tooth removed as possible, because the walls that remain are what keep the tooth from splitting under load years afterwards. This is where magnification starts to pay for itself.
Finding and measuring the canals
Under the microscope the floor of the pulp chamber can be read in detail — colour changes, the fine grooves that lead to each canal entrance, the difference between a genuine orifice and a scratch. Each canal is then measured with an electronic apex locator, which registers when the instrument tip reaches the end of the root. The measurement is confirmed on an X-ray. Getting the working length right matters in both directions: too short leaves infected tissue behind, too long irritates the bone.
Cleaning and disinfecting
The canal is shaped with fine flexible files, usually machine-driven nickel-titanium instruments that follow curves rather than straightening them. Shaping is only half the point — the other half is rinsing. Sodium hypochlorite dissolves tissue remnants and kills bacteria; further solutions remove the smear layer left by the instruments. Ultrasonic activation moves the fluid into the side branches that no file can reach. If the infection is pronounced, a calcium hydroxide dressing is left in the tooth and the treatment is completed at a second appointment.
Filling the canal
Once the canal is clean, dry and symptom-free, it is filled — typically with gutta-percha points and a sealer that fills the irregularities. In special situations, such as an open root tip or a perforation, a mineral-based material (MTA) is used to create a seal against the bone. A final X-ray documents the result.
Rebuilding the tooth
A root-treated tooth is more brittle than a live one, and a molar that has lost much of its structure usually needs a crown to survive chewing forces. Back teeth are often crowned; front teeth with modest access cavities frequently manage with a well-bonded filling. This step is not optional decoration — an excellent root filling under a leaking temporary restoration is a treatment waiting to fail.
The instruments, briefly
| Tool | What it does |
|---|---|
| Dental microscope | Magnified, shadow-free view of the pulp chamber floor, canal entrances and margins |
| Rubber dam (Kofferdam) | Isolates the tooth from saliva; keeps solutions and instruments where they belong |
| Apex locator | Electronic measurement of canal length, reducing the number of X-rays needed |
| Nickel-titanium files | Flexible shaping instruments that follow curved canals |
| Rinsing solutions | Dissolve tissue and disinfect areas no instrument reaches |
| Ultrasonic activation | Moves rinsing fluid into side canals and fine branches |
| Gutta-percha and sealer | The root filling material itself |
| MTA / bioceramic materials | Seal perforations and open root tips |
| DVT (3D X-ray) | Three-dimensional anatomy where a flat film is ambiguous |
What statutory insurance covers — and what you pay yourself
This section is the one most patients from outside Germany need, so it is set out in full.
Root canal treatment is a benefit in kind, not a subsidised service. When your fund covers the treatment, it is covered as standard care (Regelversorgung) and settled directly between the practice and the fund via your health insurance card (Gesundheitskarte / eGK). You do not pay a percentage and there is no Festzuschuss to apply for. This is different from dentures, where the fund pays a fixed share and you top up the rest.
The condition attached to molars. For front teeth and premolars, root canal treatment is normally covered where the tooth is worth preserving. For molars the fund applies preservation criteria: broadly, the treatment must keep a complete row of teeth intact, prevent a gap at the end of the row, or preserve an existing functional denture. Your practice checks the specific tooth and tells you which side of the line it falls on. If the criteria are not met, the covered alternative is extraction — you may still have the tooth treated, but then privately and in full.
Get it in writing first. Before any private item is carried out you must receive a written cost estimate and sign a private treatment agreement. The total depends on the tooth, the number of canals and the time involved, so there is no single price to quote — which is exactly why the estimate exists. Handling of individual items can differ between funds, so ask the practice to confirm your case specifically.
Supplementary and private insurance. Supplementary dental insurance (Zahnzusatzversicherung) and private cover (PKV) frequently reimburse endodontic add-ons, commonly in the region of a tariff-dependent share depending on the tariff. Submit the estimate to your insurer and wait for their written answer before booking the appointment.
The crown afterwards is a separate financial question. Here the Festzuschuss system does apply. For a single tooth requiring a crown, the fixed subsidy for 2026 is 552.96 € without regular check-up stamps, 645.12 € with a bonus booklet (Bonusheft) kept without gaps for five years, 691.20 € after ten years, and up to 921.60 € under the hardship provision (Härtefallregelung). To receive it, a treatment and cost plan (Heil- und Kostenplan, HKP) must go to your fund before the work begins — processing times vary from fund to fund. There is currently a legislative proposal under discussion that would reduce these percentages in future, with the hardship provision retained; it has not been passed, and today’s figures are the ones that apply.
What's normal afterwards — and when to contact us
A tooth that settles for weeks and then flares up again also deserves a check — that is the pattern of a canal that was missed or of a seal that has leaked, and it is discussed in Why does a root canal treatment fail?.
If German is not your first language
Endodontic appointments involve decisions taken in the chair: continue today or dress the tooth and return, save or extract, standard or private technique. Those conversations are much easier in a language you think in. Agree a hand signal for a break before the treatment starts, ask for the estimate on paper, and ask whether images from the microscope camera can be saved for you — they are the clearest record of what was found. Travelling for an English-speaking practice is entirely usual in this region: 20 to 30 minutes from Düsseldorf, Cologne, Essen or Bonn to Wuppertal is a normal journey for a treatment of this kind. See English-Speaking Dentist in NRW if you are still deciding where to go.
Endodontics is the specialist field; root canal treatment is its main procedure. The field also covers retreatment of failed root fillings, the management of dental trauma and small surgical procedures at the root tip.
The treatment itself is carried out under local anaesthetic, and most patients describe it as long rather than painful. Some tenderness for a few days afterwards is normal. For anxious patients, sedation and laughing gas (Lachgas) are available.
Frequently one or two, sometimes three when the infection is pronounced and the canal has to be dressed with medication in between. The crown, where one is needed, is a separate course of appointments afterwards.
The pulp inside has been removed, so the tooth no longer responds to cold. It remains firmly anchored in the bone by its ligament and functions normally. It is more brittle than before, which is why the restoration on top matters so much.
Usually not. Antibiotics do not reach the inside of an infected canal in useful concentrations — the treatment is mechanical. They are reserved for spreading infection, swelling or fever, and for certain medical histories.
Many last for decades. Longevity depends on how thoroughly the canal system was cleaned and sealed, on how well the tooth was rebuilt afterwards, and on your own cleaning and check-ups.
Endodontics is tooth preservation from the inside out. Under a microscope it becomes a controlled procedure rather than a search by feel: canals are found, measured, cleaned and sealed under direct vision, and the result is checked rather than presumed. In the German system the basic treatment is covered by your statutory fund when the tooth meets its criteria, while the magnification and several of the refinements are private services you agree to in writing beforehand. Ask which parts of your plan sit on which side of that line — the answer should be concrete, itemised and available before treatment begins, not on the invoice afterwards.
Zahnarztpraxis Tsypin · Wuppertal. This article was medically reviewed and is provided for information; it does not replace an examination. Updated August 2026.
