You bite into something cold and a jolt shoots through the tooth. Or you feel nothing at all, and the dentist calmly announces that there is "a small cavity on that molar". But nothing hurts.
That is the paradox: by the time a cavity hurts, it has already done a lot of work. Understanding how it is built — because it is built, day after day — completely changes how you deal with it.
How a cavity forms, concretely
It is not an accident. It is a repeated chemical reaction.
There are bacteria on your teeth. There are on everyone's, permanently: they live in dental plaque, the sticky, nearly invisible film that constantly re-forms on the enamel. That is not a sign of poor hygiene, it is biology.
Those bacteria eat the sugars you eat. Not only the sugar in dessert: all fermentable carbohydrates, including those in bread, biscuits, crisps and fruit juice.
As they digest those sugars, they produce acid. This is where everything happens. In contact with the enamel, that acid dissolves its minerals: demineralisation. The enamel loses calcium and phosphate; it weakens from within, under a surface that still looks intact.
Then your saliva repairs. That is the natural counterweight: saliva neutralises the acid and puts minerals back into the enamel. That is remineralisation. But it needs time.
A cavity is simply what happens when demineralisation wins too often against remineralisation. The enamel eventually gives way, a hole opens, and the process carries on, faster, sheltered inside the cavity.
Sugar: it is the frequency, not just the quantity
This is the most useful idea in this article, and the one you hear least.
Every sugar hit triggers an acid attack. What matters is not so much the size of the hit — it is how many times a day your mouth tips into acid, and how much time saliva gets to restore the balance in between.
In other words:
- a slice of cake eaten in one go, at the end of a meal: one attack, after which saliva works quietly for hours;
- the same amount of sugar spread across the day — a sweet here, a biscuit there, a sip of soda every twenty minutes: an almost permanent attack, and saliva never catches up.
The second scenario is far more destructive than the first, for the same amount of sugar. That is why the two real culprits are snacking and sugary drinks sipped slowly — soda, juice, sweetened coffee or tea, energy drinks, the bottle on your desk. A can drunk in five minutes is very different from the same can spread over two hours.
And the most damaging version in very young children: a sweetened bottle, or even a juice bottle, kept overnight or used to fall asleep. At night saliva slows right down — natural protection is at its lowest, and the sugar stays in contact with the teeth for hours.
None of this is a moral lesson. Nobody is asking you never to eat dessert again. You are being asked to group sugar rather than spread it. That is a change of organisation, not of pleasure.
Fluoride: the cornerstone of prevention
If you remember only one measure, make it this one.
Fluoride works in two ways: it makes enamel more resistant to acid attack, and it promotes remineralisation of areas already under attack — it helps saliva do its repair work, and can stop an early lesion before it becomes a hole.
What matters most is its local action, in contact with the tooth. Concretely, that means something very simple: fluoride toothpaste, morning and night. It is by far the highest-yield habit in your entire oral hygiene routine.
Two tips that genuinely change how well it works:
- the evening counts more than the morning. Saliva falls at night; a tooth brushed with fluoride before bed spends the night protected;
- spit, but do not rinse heavily with water straight after brushing. Rinsing with lots of water washes away the fluoride you have just applied. Letting the film work is free, and it is effective.
In children, the amount of toothpaste is adapted to age, and that is the only real precaution to know: ask your dentist, who will also adapt to your child's individual risk (they may apply fluoride varnish, or seal the deep grooves of the molars — those crevices a brush cannot reach). The World Health Organization treats fluoride exposure as a pillar of oral health, and the NHS sets out the same practical advice.
The rest of the toolkit takes few words: clean between your teeth (floss, interdental brushes) — because the brush does not go there, and many cavities start exactly there; limit the frequency of sugar hits; and see a dentist regularly, because they see what you cannot.
Unsure about a tooth, a cold sensitivity that has settled in, or simply a check-up you have been putting off? Find a dentist near you on OlamKal and book your slot in a few clicks.
What you should know, honestly
Three uncomfortable truths that will save you teeth.
A cavity does not hurt at first. Enamel has no nerve. As long as the lesion stays there, you feel absolutely nothing. Sensitivity to cold or sweetness appears once decay reaches the deeper dentine; real pain, the kind that keeps you awake, once it approaches the nerve. The absence of pain proves nothing — and that is the whole point of regular check-ups: they catch lesions you had no way of knowing about.
A cavity does not heal itself once the hole has formed. The essential nuance: early demineralisation, the chalky white spot whose surface is still smooth, can be stopped — fluoride, fewer sugar hits, good brushing. There, yes, you can turn things around. But once the surface has collapsed and a hole exists, the lost tissue does not grow back. No toothpaste, no mouthwash, no remedy will change that. It needs the chair.
An antibiotic does not treat a cavity. In certain infectious situations it may accompany treatment, on the dentist's prescription. But it does not remove destroyed tissue and does not close the tooth. If pain has settled with an antibiotic, the problem is not solved: it is waiting.
Treatment: saving the tooth, first
The principle that guides all modern dentistry: we try to keep the tooth. Extraction is the end of the road, when there is nothing left to save.
Very early — the lesion without a hole. The tooth is not drilled. It is monitored and strengthened: fluoride application, a look at sugar habits, brushing technique, possibly sealing the grooves. The aim is to arrest the lesion.
Decay that has made a hole — the filling. This is the commonest treatment. The dentist anaesthetises if needed, removes the softened, infected tissue, cleans the cavity, then rebuilds it with a material that bonds to the tooth and restores its shape and strength. The tooth is kept, alive and working. Done early, it is a straightforward appointment.
Decay that has reached the nerve — root canal treatment. When inflammation or infection reaches the pulp (the nerve, at the heart of the tooth), it has to be removed: the dentist cleans and disinfects the canals, then seals them. The tooth, now non-vital, becomes more brittle and is often protected with a crown. It takes longer — but the tooth is kept, and that is the whole point.
Extraction — the last resort. When the tooth is too broken down or fractured, or its bony support is too damaged for it to hold, it is removed. It is never a first choice: every missing tooth unbalances the rest, neighbours drift, chewing changes, bone resorbs. Your dentist will then talk to you about replacement. A treated tooth is far better than a replaced one — which is exactly why you do not postpone that appointment.
Your dentist is a qualified dental surgeon: they examine, X-ray when needed, prescribe, treat and, when they must, extract. The right time to see them is before they have to choose the last option.
When to call 101
A dental infection is not always harmless. It can spread into the tissues of the face, the floor of the mouth and the neck, and threaten the airway. It is rare, but it is serious, and it can move fast.
Call 101 immediately, or go to the emergency department, if you notice:
- swelling of the face or neck that is spreading, under the jaw, into the neck or towards the eye;
- difficulty swallowing or breathing, a muffled voice, saliva you can no longer swallow;
- high fever together with tooth pain or swelling;
- inability to open your mouth normally.
These are life-threatening emergencies: you do not wait for morning, you do not wait and see. Outside of these signs, severe toothache, a localised abscess or a broken tooth call for a prompt dental appointment, not 101.
Finally
A cavity is not a punishment, nor proof that you brush badly. It is the result of an imbalance between acid attacks and your mouth's ability to repair — and that imbalance can be corrected, if you catch it in time.
Fluoride every evening, cleaning between the teeth, and above all: group your sugar hits rather than spreading them out. Then let a dentist regularly look at what you cannot see. That is where the difference lies between a small filling and a root canal.
For your rights and dental care in Israel, the reference is the Israeli Ministry of Health.
Can't remember when your last check-up was? That is precisely the moment. Book an appointment with a dentist near you on OlamKal, and get checked for what cannot yet be seen.
