Lecture 6 Enamel Dental Pulp

Question 1

AMELOGENESIS

Answer 1

• Process of enamel matrix formation and mineralization
• Enamel matrix is ectodermal and is derived from Inner
Enamel Epithelium (IEE) of the enamel organ (more on this later)
• Occurs during the appositional stage (formation of enamel/dentin matrix) of tooth development
• Enamel matrix at first is composed of proteins, carbohydrates and small amounts of calcium hydroxyapatite crystals:
• it does not contain collagen proteins like dentin, cementum and alveolar bone.
• Dentin must be present

Question 2

Ameoblasts

Answer 2

• Enamel is 1st formed in the cusp/tip area of a tooth
• Ameloblasts:
- produce enamel matrix

Question 3

Tomes Process

Answer 3

• Tomes process:
- secretes enamel matrix
Enamel organ
- 6 sided pyramidal shaped projection of ameloblast, facing the DEJ.
Enamel
• Ameloblasts are not
matrix -
differentiated in the root Predentin
Predentin -
area:
- therefore, enamel is present on the anatomical crown area only

Question 4

Developmental Disturbances

Answer 4

Developmental Disturbances
• Enamel pearl:
- small, spherical enamel projections on root surface
• Enamel dysplasia:
- faulty development of enamel
• Deepened pits and fissures:
- common; occurs when ameloblasts back into one another during the stage of apposition, cutting off their source of nutrition, which causes incomplete maturation of enamel
matrix
- these weakened areas may become target areas for dental caries
• Sealants: used in preventing cavities

Question 5

When ameoblasts are done making enamel