TL;DR: Tooth decay progresses from early demineralisation of enamel, which can sometimes be reversed, to cavities, deeper decay reaching the nerve, and finally infection that can form an abscess. Treatment becomes more complex at each stage. Early detection at check-ups, fluoride toothpaste, and less frequent sugar intake reduce the risk. This guide has 9 sections and answers 3 frequently asked questions. It lists 5 primary sources, from NHS.uk, NICE and GOV.UK. Facts were checked on 2026-10-13; it is educational information, not clinical advice.
Educational information only, not clinical advice. Facts are checked against the primary sources listed under Sources (NHS.uk, GDC, CQC and peer-reviewed research), last checked 13 October 2026.
What causes tooth decay?
Tooth decay happens when bacteria in plaque turn sugars into acid that dissolves the tooth’s mineral surface. Frequent sugary food and drink, poor cleaning, and dry mouth increase risk. NHS.uk describes decay as largely preventable.
What is the first stage of tooth decay?
The first stage is demineralisation, in which acid removes minerals from the enamel. It can appear as white or chalky spots and usually causes no pain. At this stage, fluoride, better cleaning, and reduced sugar intake can help the enamel repair itself. A dentist may apply fluoride varnish.
What happens when decay breaks through the enamel?
When the enamel surface breaks down, a cavity forms. Sensitivity to sweet, hot, or cold food may begin, and the spot may look brown or black. A cavity does not heal by itself. The dentist removes the decayed part and places a filling. See sensitive teeth causes.
What happens when decay reaches the dentine and pulp?
Decay that passes through enamel reaches the softer dentine, where it spreads faster. If it reaches the pulp, the nerve and blood supply, pain can become more intense, with lingering or night-time toothache. Treatment may involve a larger filling, root canal treatment, or extraction.
What is a dental abscess?
A dental abscess is a collection of pus caused by bacterial infection at the tooth root or in the gum. Signs include throbbing pain, swelling, a bad taste, fever, and tenderness when biting. An abscess needs prompt dental care. Facial swelling that affects breathing or swallowing needs 999 or A&E, and NHS 111 can guide urgent access.
How can I reduce the risk of decay?
The NHS advises brushing twice daily with fluoride toothpaste, spitting instead of rinsing, limiting how often sugary food and drink are consumed, and attending regular check-ups. The interval between check-ups is set by the dentist based on risk, following NICE guidance on dental recall. Children may benefit from fluoride varnish, which the dentist can apply.
For related issues, see gum disease and plaque and tartar removal.
Where can I get help?
Book a check-up if you notice spots, holes, or sensitivity. NHS charges apply by band unless you are exempt. Check current fees on NHS.uk. You can browse Essex dentists in the Essex directory.
Does decay always hurt?
No. Early decay is often painless. Pain tends to arrive late, when the problem is larger. Routine check-ups find what you cannot feel.
In the 2024 national survey of five-year-olds (National Dental Epidemiology Programme, updated 5 March 2025), 22.4% in England had experienced visually obvious decay into the dentine. The figure for the East of England was 17.5%. The survey publishes no separate figure for Essex.
What should I do, depending on what I notice?
| What you notice | Suggested action |
|---|---|
| Facial or neck swelling with trouble breathing or swallowing | 999 or A&E now |
| Swelling, fever, bad taste, severe throbbing pain | Contact a dentist today; NHS 111 if closed |
| Sensitivity or a visible hole, no swelling | Book a dental appointment |
| White or chalky patches, no pain | Mention at your next check-up; brush with fluoride toothpaste |
A clinician makes the final judgement.
Related questions covered elsewhere in this topic: dental hygienist visit.
To find a practice, browse dentists in Essex by district.
FAQ
Can early decay be reversed?
Very early enamel changes can sometimes remineralise with fluoride and better habits. A dentist confirms the stage.
Does decay always hurt?
No. Early decay often causes no pain, which is why check-ups matter.
Is toothache always decay?
No. Gum problems, cracks, and sinus issues can also cause pain. A dentist diagnoses the cause.
Sources
- NHS.uk, Tooth decay: https://www.nhs.uk/conditions/tooth-decay/
- NHS.uk, Dental abscess: https://www.nhs.uk/conditions/dental-abscess/
- NICE CG19, Dental checks: https://www.nice.org.uk/guidance/cg19
- NHS.uk, How much will I pay for NHS dental treatment: https://www.nhs.uk/nhs-services/dentists/how-much-nhs-dental-treatment-costs/
- OHID, National Dental Epidemiology Programme: oral health survey of 5 year old schoolchildren 2024: https://www.gov.uk/government/statistics/oral-health-survey-of-5-year-old-schoolchildren-2024/national-dental-epidemiology-programme-ndep-for-england-oral-health-survey-of-5-year-old-schoolchildren-2024