Structure and what follows from it
Enamel is built from densely packed hydroxyapatite crystals arranged in rods running from the dentin surface outward. This gives extraordinary hardness and wear resistance, which is why teeth survive decades of chewing. The trade-off is brittleness and, more importantly, the absence of cells. Bone remodels because it contains living osteocytes and a blood supply. Enamel has neither, so it cannot repair damage biologically.
| Property | Enamel | Dentin | Bone |
|---|---|---|---|
| Mineral content | ~96% | ~70% | ~60% |
| Living cells | None | Odontoblast processes | Yes |
| Can regenerate | No | Limited (reparative) | Yes |
| Sensation | None | Yes | Yes |
Demineralisation and remineralisation — the one reversible window
Enamel is in constant chemical exchange with saliva. When plaque bacteria produce acid after a sugar exposure, or when acidic food or drink lowers the pH, mineral leaves the surface. When saliva restores neutral pH and supplies calcium and phosphate, mineral returns. Fluoride shifts this balance decisively in favour of repair and forms a more acid-resistant mineral.
A white spot lesion is demineralised but not yet cavitated enamel — chalky, opaque, and still structurally continuous. This is the last genuinely reversible stage of decay, and it can be arrested or reversed with fluoride, plaque control, and reduced sugar frequency. Once the surface collapses into an actual cavity, no amount of fluoride rebuilds the missing structure and a filling is required. Recognising white spots and acting on them is one of the highest-value things preventive dentistry does.
Erosion versus decay — different mechanisms, different fixes
- Decay is bacterial: plaque metabolises sugar and produces acid locally, so lesions appear in plaque-retentive sites such as grooves and between teeth. Managed by plaque control, fluoride, and reducing sugar frequency.
- Erosion is chemical without bacteria: acid contacts the tooth directly. Sources include carbonated drinks, citrus, sports drinks, wine, vinegar-based foods, and, importantly, gastric acid from reflux or vomiting. It produces broad, smooth, shiny loss rather than discrete holes, and the palatal surfaces of upper front teeth are often affected first in reflux.
- Abrasion is mechanical: over-vigorous brushing with a hard brush, particularly with abrasive whitening pastes, producing notches at the gumline.
- Attrition is tooth against tooth — the wear pattern of grinding, flattening cusps and shortening front teeth.
Protecting what you have
- Fluoride toothpaste twice daily, and do not rinse with water afterwards — spit only, so the fluoride stays in contact.
- Reduce acid and sugar frequency rather than only quantity. Six small sips of a soft drink across a day is far more damaging than one glass in ten minutes, because each exposure restarts the acid cycle.
- Use a straw for acidic drinks, and avoid swishing or holding them in the mouth.
- Soft brush, gentle pressure. Effective cleaning is about technique and coverage, not force.
- Investigate reflux if erosion appears on the palatal surfaces of upper teeth, since dental erosion is sometimes the first sign of it.
- Protect against grinding with a splint if attrition is present.
Notes for patients based in Korea
Enamel loss is progressive and painless, so an examination that finds early white spots or the beginnings of erosion is genuinely worth more than one that finds nothing wrong. If you have moved between countries, ask for copies of previous radiographs, since comparison over time shows progression that a single snapshot cannot. We are around 30 minutes from Camp Humphreys with English-language consultation, and preventive and restorative fees are listed on our English price page. Book a check-up.