Receding gums and sensitive tooth necks: why exposed roots ache

When the gum edge slides towards the root, it uncovers a part of the tooth built to stay hidden. The exposed neck and root carry no enamel at all — only a layer of cementum thin enough to wear through within a few years of ordinary brushing — so cold, air and sugar reach the nerve almost unfiltered. That is why receding gums (Zahnfleischrückgang) and sensitive teeth so often arrive together. Gum that has receded does not grow back on its own, and no toothpaste brings it back. What can be done is to stop the recession going further and take the sting out of what is exposed — and both are usually achievable with modest measures.

A tooth is two different materials wearing one shape. Above the gum line sits the crown, capped with enamel — the hardest substance the body produces, chemically inert, with no nerve supply of its own. Below the gum line sits the root, and the root has no enamel. It is covered by cementum, a soft mineralised layer measured in fractions of a millimetre, which exists to anchor the fibres that hold the tooth in its socket. Nature’s plan for cementum is that it stays buried in the gum and never meets a toothbrush.

The tooth neck (Zahnhals) is the seam where those two materials meet. It is the most vulnerable point on the whole tooth: enamel is at its thinnest there, cementum begins, and in a proportion of people the two do not quite meet, leaving a strip of bare dentine at the join.

Once the gum retreats past that seam, three things follow. Cementum wears through under ordinary brushing within a few years. The dentine beneath is exposed — and dentine is riddled with microscopic fluid-filled channels running straight to the nerve. And the root surface, softer and rougher than enamel, holds plaque more readily and decays faster than the crown ever would.

Sensitivity, in other words, is not the recession itself. It is the consequence of a surface losing its cover.

Recession comes in two broad varieties, and the difference decides what happens next. Inflammation-driven recession goes with gums that bleed when brushed and look red and puffy: the attachment and the bone beneath it are being lost, and the gum follows them down. Mechanical recession happens on healthy tissue — a hard brush used with force, a thin gum type that runs in families, grinding, a lip or tongue piercing, a tooth standing slightly outside the arch. Here the gum stays pale and firm, the recession forms a clean V on the surfaces you brush hardest, and there is often a polished notch worn into the neck.

Bleeding is the quickest way to tell them apart, and plenty of people have some of each. Exposed tooth necks: how to spot them early reads the patterns tooth by tooth. For sensitivity the distinction matters for one practical reason: inflammation has to settle before anything is sealed or covered, because work done on inflamed tissue tends not to hold.

Cold, air and sweetness all do the same thing: they make the fluid inside those channels move suddenly, which tugs on nerve endings at the inner end and produces a short, sharp stab that stops the moment the trigger goes. It is a mechanical event rather than an infection, which is why sealing the channels calms it. Pain that lingers past half a minute, throbs, or wakes you at night works differently and needs examining — Sensitive teeth but no cavities: why perfectly healthy teeth can still hurt covers the other causes of sensitivity in full.

The honest answer to the first half is no. Gum that has detached and moved down does not climb back up, and nothing in a tube regrows it. The second half is where the good news sits: the sensitivity can almost always be reduced, and that is the part you actually feel.

Three things do that work. Removing the cause — plaque, brushing pressure, grinding load, a piercing — stops the recession progressing in the great majority of cases. Sealing the exposed surface calms the nerve: fluoride varnish and desensitising agents in the practice for smooth areas, tooth-coloured composite for a notch that has already worn in, usually in one appointment and often without local anaesthetic (Betäubung). And where a single tooth genuinely warrants it, covering the root surgically is a planned option to discuss with a specialist, once the mouth is free of inflammation.

One thing that confuses people: when swollen gum settles after treatment, more of the neck becomes visible and sensitivity can briefly increase. That is the inflammation leaving, not the recession accelerating.

The eye adapts to slow change, so recession is measured rather than estimated. A blunt calibrated probe records the distance from the enamel junction to the gum margin in millimetres, tooth by tooth, alongside pocket depths and bleeding points. Repeat that at the next visit and the comparison, rather than the impression, says whether anything has moved. A digital scan with Primescan adds a three-dimensional record of where your gum margin sits today, which can be overlaid a year later. Under the microscope the detail at the neck becomes readable — whether a notch is simple wear, an old filling edge standing proud, or early decay on the root surface. Those three look identical at arm’s length and need three different answers.

Change the brush and the motion, not just the toothpaste. Soft filaments, or an electric brush with a pressure sensor you let stop you; small circles or short strokes angled towards the gum, never a horizontal saw. A head that splays outwards within a couple of months is the problem in visible form.

Clean between the teeth gently. Interdental brushes (Interdentalbürsten) in a size that slides in with slight resistance. One that is too large, forced into the gap, is itself a cause of recession.

Use fluoride deliberately, and wait after acid. A high-fluoride gel once a week, or a desensitising paste rubbed onto the spot at bedtime and not rinsed off — give either two to four weeks. Enamel and cementum both stay softened after anything acidic, so rinse with water and brush later.

Deal with the load and the smoke. A night guard (Knirscherschiene) where grinding flexes the necks, and stopping smoking, which drives gum disease and hides it by suppressing the bleeding that would have warned you.

Bleeding deserves a line of its own, because it is the most commonly ignored sign in dentistry — Bleeding gums: how serious is it? explains what it does and does not mean.

Thin gums. A delicate, translucent gum type with very little bone over the front roots is inherited, and it makes technique matter far more than usual: aggressive brushing costs such a person real tissue where a thicker type would shrug it off.

During orthodontic treatment. Moving a tooth outwards through a thin plate of bone can pull the gum with it. Clear aligners (Aligner) and fixed braces (feste Zahnspange) both need healthy gums before treatment starts and monitoring while it runs — recession appearing mid-treatment is a reason to review the plan rather than press on.

Piercings. A lip or tongue stud resting against one spot produces a textbook single-tooth recession, and it is one of the few causes where removing the object halts the process immediately.

Pregnancy. Hormonal changes make gum tissue react far more strongly to the same plaque. Swelling and bleeding are common and treatable; the second trimester is the most comfortable window for anything planned.

You are new to Germany. Describing a twinge in a second language while someone holds a mirror in your mouth is genuinely hard, and gum problems get postponed for exactly that reason. Here you can explain it in English and hear the findings in English — English-Speaking Dentist in NRW covers how check-ups and cost plans work when the system is new to you. Worth knowing too: your annual check-up earns a stamp in the bonus booklet (Bonusheft), which raises your fund’s contribution years later if you ever need a crown or denture.