Tooth decay is not a sudden event—it is a dynamic process driven by the balance between demineralisation (mineral loss) and remineralisation (mineral gain).
Whether a lesion progresses or heals depends on which process dominates over time.
Acid Attack and Early Lesion Formation
Every time we eat or drink fermentable carbohydrates (especially sugar), oral bacteria produce acid. This causes an “acid attack” on enamel.
Early changes include:
- White spot lesions – early subsurface enamel demineralisation
- Intact surface enamel with mineral loss underneath
If repeated acid attacks continue, lesions can progress into cavities.
Histological Zones of Enamel Caries
Early enamel caries shows distinct layers:
- Surface zone – relatively intact enamel
- Body of the lesion – greatest mineral loss
- Dark zone – partial remineralisation occurring naturally
- Translucent zone – advancing front of demineralisation
The presence of a dark zone is important—it indicates the tooth is attempting repair through remineralisation.
Active vs Arrested Lesions
Active Lesions
- Chalky, matte white appearance
- Rough surface
- Located in plaque-retentive areas
- Progressing over time
Arrested Lesions
- Hard, shiny surface
- May appear darker or brown
- No longer progressing
- Indicates successful remineralisation or plaque control improvement
Arrested lesions often do not require restorative treatment, only monitoring and prevention.
What Favors Demineralisation?
Demineralisation dominates when:
- Frequent sugar intake (high frequency more important than total amount)
- Constant snacking or sipping sugary drinks
- Poor oral hygiene and plaque accumulation
- Dry mouth (reduced saliva buffering)
- Acidic diet (soft drinks, energy drinks, citrus exposure)
- Lack of fluoride exposure
What Favors Remineralisation?
Remineralisation is supported by:
- Adequate saliva flow (natural buffering and mineral supply)
- Fluoride exposure (toothpaste, varnish, high-risk products)
- Time between acid exposures
- Good plaque control
- A diet low in frequent fermentable carbohydrates
White Spot Lesions and Non-Cavitated Lesions
White spot lesions represent non-cavitated enamel caries. At this stage:
- The enamel surface is still intact
- The lesion is potentially reversible
- With good control, lesions can arrest or remineralise
If progression continues, the surface breaks down and a cavity forms.
Diet: Frequency Matters More Than Quantity
A key concept in caries development is that the frequency of sugar exposure is more important than the total amount consumed.
Higher risk patterns include:
- Frequent snacking throughout the day
- Sugary drinks sipped over long periods
- Bedtime sugar exposure without cleaning
Lower risk patterns include:
- Sugar is consumed with meals only
- Long gaps between acid exposures
- Water or non-sugary drinks between meals
Prevention and Clinical Control
Effective prevention focuses on shifting the balance toward remineralisation:
- Twice-daily brushing with fluoride toothpaste
- High-fluoride toothpaste for high-risk patients
- Regular dental check-ups and early detection
- Professional fluoride varnish application
- Interdental cleaning to reduce plaque retention (flossing, interdental brushes, water flossers)
- Dietary counselling focused on reducing the frequency of sugar intake
- Saliva support (hydration, sugar-free gum, managing dry mouth)
Key Message
Tooth decay is not just “holes in teeth”—it is a balance between ongoing damage and natural repair. If remineralisation is stronger than demineralisation, early lesions can stabilise or even improve.
If you are concerned about early decay or white spots, the team at Dural Dental Practice can assess your risk and help you prevent progression before cavities develop.
