What is the hardest component of the body?
Enamel- 96% mineralized made up of calcium and phosphate crystals
Describe the production of enamel during tooth development
1) Ameoblast secretes amelogenin and enamelin
2) Matrix is mineralized
3) Organic material removed from material and replaced by more Ca and P
4) tooth erupts and ameoblasts fall off
How are enamel rods configured?
- key hole configuration
- each rod is produced by an ameloblast
- oriented obliquely around tooth
Can you see enamel in sections of teeth?
Yes, but only in ground teeth. The growth lines are the horizontal lines in the picture.
What type of cells produce dentin?
Odontoblasts
Where are odontoblasts found?
Pulp cavity
What do odontoblasts produce?
Predentin- unmineralized organic matrix
What do odontoblasts leave behind when they retreat?
Odontoblastic process in the dentinal tubule. Dentin becomes mineralized
What makes up dentin?
- Type 1 collagen
- Ground substance (Glycosaminoglycans)
- Hydroxyapatite crystals (more than bone, harder)
What is in tooth pulp? (6)
1) Blood vessels
2) Collagen
3) Fibroblasts
4) Immune cells
G) Odontoblasts
H) Pain nerve fibers
How does the tooth stay in the socket?
Periodontum- the tissues involved in attachment of tooth to bone
What makes up the periodontium? (4)
- Gingiva
- Cementum
- Periodontal Ligament
- Alveolar Bone
What tissue makes up the free gingiva?
Stratified squamous epithelium, keratinized
Is the sulcular epithelium keratinized?
No
In the junctional epithelium keratinized?
No
What helps join the junctional epithelium to the tooth?
Hemidesmosomes
What cells make cementum?
Cementoblasts
Which cells in the PDL produce the ground substance and Type 1 collagen fibers?
Fibroblasts
What are the functions of the PDL? (5)
- connect bone to cementum
- absorb shock
- sensory
- blood supply/nutriends
- remodeling via mesenchymal stem cells into osteoblasts, fibroblasts, or cementoblasts
