Caries Diagnosis, Risk Assessment and Minimal Care Guide

Dental caries (tooth decay) is the destruction of tooth structure by acids that mouth bacteria produce from sugars. Caries diagnosis finds decay as early as possible, risk assessment predicts who will develop more, and minimal intervention dentistry treats it with the smallest effective procedure — preserving natural tooth wherever possible.

The old "drill every dark spot" habit sacrificed healthy tooth, and every filling eventually needs replacement with something larger. Catching decay at the white-spot stage and remineralising instead of drilling keeps teeth whole for decades longer.

Key Concepts

• Demineralisation vs remineralisation: acids dissolve minerals; saliva and fluoride rebuild them. Cavities form only when the balance stays negative.
• Streptococcus mutans: the main acid-producing bacterium behind caries, thriving on frequent sugar.
• ICDAS: scores lesions 0 (sound) through 1–2 (early visual changes), 3–4 (enamel breakdown, underlying shadow) to 5–6 (distinct/extensive cavities).
• Bitewing radiographs: reveal decay between back teeth long before it is visible.
• CAMBRA: Caries Management by Risk Assessment — weighs diet, saliva, fluoride, bacterial load and past decay to grade risk low to extreme.
• Minimal intervention tools: fluoride varnish, pit-and-fissure sealants, silver diamine fluoride (arrests decay), CPP-ACP remineralising cream, and atraumatic restorative treatment (ART).

How It Works

A modern caries visit runs in order: history (diet, fluoride, past decay), visual exam of clean dried teeth scored with ICDAS, bitewing radiographs for contact areas, then the CAMBRA risk form. The plan follows risk: low-risk patients get fluoride toothpaste and routine recall; moderate-risk add sealants and periodic varnish; high-risk get antibacterial measures, diet counselling and shorter recalls. Only cavitated lesions (ICDAS 3 and above, roughly) are restored — early white spots are remineralised, not drilled.

Worked Example

Fluoride dose in a brushing. Standard toothpaste has 1000 ppm fluoride = 1000 mg per kilogram = 1000 mg per 1000 g, i.e. 1 mg per gram of paste. A pea-sized dab weighs about 0.25 g, so one brushing applies 1 × 0.25 = 0.25 mg of fluoride. Twice daily gives about 0.5 mg a day bathing the teeth — enough to tip the balance toward repair, which is why risk assessment always starts by confirming fluoride toothpaste use.

Common Misconceptions

• Every small cavity must be drilled. White-spot lesions (ICDAS 1–2) can reharden with fluoride — drilling them destroys healthy tooth for no benefit.
• Sugar-free drinks are safe. Many are still acidic and erode enamel; acid-attack frequency matters as much as sugar.
• Baby teeth do not matter. Their decay spreads fast, causes pain, and can damage developing permanent teeth.

Real-World Applications

• School screening camps, where ICDAS scoring finds early lesions in hundreds of children.
• Paediatric dentistry: varnish and sealants preventing most decay without a drill.
• Public-health programmes using ART and silver diamine fluoride where full clinics are unavailable.

Diagnose early, assess risk honestly, intervene minimally: that trio replaced the drill-first era. The best filling is the one never needed — and risk-based prevention is how dentistry earns it.