CARIOLOGY: HISTOLOGIC FEATURES OF ENAMEL CARIES

History of caries lesion and information for non/invasive treatment

Reason for interest in clinical appearance

Understanding Disease Process

What is provided by histology of caries

Shape of Lesion

Reflects where biofilm has been allowed to grow

Developmental Pits and Fissures, SES, Root Surfaces

3 clinical sites for caries initiation

Developmental Pits and Fissures

Site most susceptible to caries

Smooth Enamel Surface

Site sheltering cariogenic biofilm

Enamel Prism/Rods/Prism Borders/Striations , Band of Retzius and Surface zone

Basic structures of normal enamel

White Spot

Earliest evidence of caries on SES

Can

Non cavitated caries can or cannot be remineralized?

Retains most of original crystalline framework of enamel rods

What occurs on enamel rods in non cavitated caries

Retained Crystalline Framework of Enamel Rods

Serves as nucleating agents of remineralization

Calcium and Phosphate Ions

Ions from saliva that penetrate enamel surface and precipitate on highly reactive crystalline surfaces of enamel lesions

Fluoride Ions

Enhances precipitation of Calcium and Phosphate Ions in remineralization

More Resistant

Effect of Fluoride ions on remineralized enamel

Fluorapatite

Acid-resistant substance that makes remineralized enamel more resistant

4 Microscopic Zones of Caries

Translucent Zone, Dark Zone, Body of Lesion, Surface of Lesion

Translucent Zone

Innermost zone and the advancing front of caries

Dark Zone

Immediately above Translucent Zone

6% Mineral Loss

Demineralization percentage exhibited in Dark Zone

Body of Lesion

Area of maximum demineralization occupying major portion of the lesion

Striae of Retzius

Structure that is enhanced by Body of Lesion

20-100 um

Thickness of Surface Lesion

Inactive lesion

Where surface lesion is thicker

Active Lesion

Where surface lesion is thinner

10% Mineral Loss

Percentage of demineralization in surface of lesion

Prism Sheaths

This structure is broadened bu the Surface of Lesion making it its characteristic feature