ID 3 Tooth anatomy and tooth supporting structures Flashcards
What are the 3 main dental tissues
2) What surrounds the roots
1) Enamel, Dentine, Pulp
2) Cementum
What are the functions of the teeth
Mastication
Appearance
Speech
Maintaining vertical position and jaw guidance
Describe the following for Enamel:
1) Colour
2) Mineral Content
3) Hardness
4) Resilience
5) Living or nonliving
1) White
2) 95%
3) Extremely hard
4) Brittle
5) Nonliving
Describe the following for Enamel
6) Formative cell
7) nutritive cell
8) Requirements for nourishment
9) Sensitivity
10) Repair Potential
6) Ameloblast
7) none
8) no
9) no
10) no
state the following for Enamel:
1) Colour
2) Mineral Content
3) Hardness
4) Resilience
5) Living or nonliving
1) White
2) 95%
3) Extremely hard
4) Brittle
5) Nonliving
state the following for Enamel
6) Formative cell
7) nutritive cell
8) Requirements for nourishment
9) Sensitivity
10) Repair Potential
6) Ameloblast
7) none
8) no
9) no
10) no
state the following for Dentine:
1) Colour
2) Mineral Content
3) Hardness
4) Resilience
5) Living or nonliving
1) cream
2) 70%
3) hard
4) very resilient (not brittle)
5) living
state the following for Dentine
6) Formative cell
7) nutritive cell
8) Requirements for nourishment
9) Sensitivity
10) Repair Potential
6) Odontoblast
7) Odontoblast
8) Yes
9) Yes-pain
10) yes
state the following for Cementum:
1) Colour
2) Mineral Content
3) describe Hardness
4) Resilience
5) Living or nonliving
1) cream
2) 61%
3) softer than dentine; harder than bone
4) tough
5) living; may die in maturity
state the following for Dentine
6) Formative cell
7) nutritive cell
8) Requirements for nourishment
9) Sensitivity
10) Repair Potential
6) cementoblast
7) none or cementocytes
8) no
9) no
10) yes
What compound does enamel mainly consist of?
calcium hydroxylapatite
What is the crystalline structural unit of enamel?
How many of these can an ameoblast make?
How are they linked together?
enamel prism
1
Many rods come together with complex interconnecting structures along their length, they form a long curve in vertical plane of sections and undulate up and down in the plane of the section
What are ameloblasts
cells present only during tooth development that deposit tooth enamel, which is the hard outermost layer of the tooth forming the surface of the crown
What is decussation ( when applied to enamel)
The way in which the enamel prisms come together form a long curve in vertical plane of sections and undulate up and down in the plane of the section
What is predentine?
a band of newly formed, unmineralised matrix of dentine at the pulpal border of the dentine
What is _________ dentine?
1) Primmary
2) secondary
3) tertairy
1) formed before completion of root
2) Formed after after root formation
3) Formed due to damdge
what are the 2 types of tertiary dentine, what is the difference between them?
1) 3’ reactionary dentine- formed by original odontoblasts, in reaction to small stimulus/ injury
2) 3’ reparative dentine- formed by newly recruited odontoblasts when repair is required as big injury
What is present in the pulp?
1) Fibrous connective tissues (collagen)
2) Blood vessels and nerves
3) some cells
4) sometimes pulps stones
Where do Blood vessels and nerves enter the tooth?
apical foramen and accessory canals
What cells are present in the pulps?
odontoblasts, fibroblast, undifferentiated cells & defence cells
What are the causes of pulp stones?
- injury
- Age-related, older pulp are less vascular (fewer blood vessels) and get mineralised in the form of pulp stones
Why is fissure sealant applied to molars and premolars?
To fill in occlusal fissures as as frequent site of carries since it cannot be kept clean with toothbrush bristles
What 4 tissues make up the periodontium?
1) Gingiva
2) Periodontal ligament
3) Alveolar bone
4) Cementum
What is the function of the periodontium?
1) attach teeth to jaws
2) Support teeth during chewing- loads create lateral & horizontal movements
What is attached gingiva attached to? what polymer does it contain?
attached to underlying bone, keratinized (has keratin- makes things tough)
What is the free gingiva?
Where is it?
What colour is it?
What polymer is present in it?
- not free but movable
- Extends from gingival margin to bottom of gingival sulcus
- light pink
- both keratinized and non-keratinized
What is the function of the junctional epithelium?
Where is it in healthy teeth?
What is a property of the junctional epithelium?
- attaches gingiva to enamel
- apically (bottom of) at cemento-enamel junction
- permeable or “leaky” - less tight junctions between cells- allow crevicular fluid to flow into sulcus (crevice) with immune defence cells
What is the function of keratin?
keratin protects the tissue from damage due to abrasive forces during mastication
What is the function of keratin?
keratin protects the tissue from damage due to abrasive forces during mastication
What is the function of the periodontal ligament?
connect Cementum and alveolar bone
What cells does the periodontal ligament contain and for what function:
1) Cementoblast- form cementum
2) fibroblasts- form fibres
3) Osteoblasts - form bon
What is the periodontal ligament?
Why is it important it has this strucuture?
-Dense, fibrous connective tissue where the collagen fibres are orientated in groups (bundles) for maximal strength, This is important as it means fibre bundles can resist intrusion (moving of tooth into alveolus) of tooth during mastication.
What are sharpey’s fibres?
principle fibres embedded in bone and cementum that are a part of periodontal ligaments
What are the properties of Periodontal ligament or membrane?
- stong: due to orientation of fibres in bundles
- high rate of cell turnover
- heals quickly: due to rich vascular supply
- sensory & pain response: rich innervation
What are the properties of Periodontal ligament or membrane?
- stong: due to orientation of fibres in bundles
- high rate of cell turnover
- heals quickly: due to rich vascular supply
- sensory & pain response: rich innervation
What are the 2 tooth supporting structures (so are part of periodontium) that are mineralised connective tissue?
Where are they in relation to the periodontal ligaments?
- Cementum
- Alveolar Bone
attached either side of it
Cementum
1) Where is the acellular cementum?
2) Where is the cellular cementum?
3) How fast does it grow?
1) covering roots, at the top as Aces everything
2) around apex of tooth (got a C so is at bottom of class)
3) Grows slowly and accumulates throughout life
What is the alveolar bone? what does it do?
Its part of maxilla & mandible that supports roots of teeth
whats the alveolar bone called on a radiograph?
lamina dura
What happens to alveolar bone if it receives no stimulus from functional teeth?
resorbed by osteoclasts if no stimulus from functional teeth
How big is the pocket in moderate periodontal disease?
4-5.5mm
How big is the pocket in severe periodontal disease?
+6mm
