CE: The Host

Question 1

what is the host?

Answer 1

tooth structure, saliva surrounding tooth, and immune response of saliva/plasma

Question 2

Caries don’t develop w/o presence of

Answer 2

host

Question 3

Tooth has 4 major tissues which are?

Answer 3

enamel, dentin, dental pulp, cementum

Question 4

Enamel

Answer 4

Most mineralized tissue of the body, very hard, thin, translucent layer of calcified tissue that covers the entire anatomic crown of the tooth, vary in thickness and hardness and color

Question 5

What does the enamel consist of?

Answer 5

No n. or blood supply w/n
Hardness allows teeth to w/stand blunt/heavy masticatory forces
- 95-98% of its Ca & P make up strong hydroxyapatite crystals
- 1-2% of enamelin proteins that have high affinity for binding hydroxyapatite crystals
- 4% water

Question 6

Rod

Answer 6

Carbonated hydroxyapatite crystals arranged in long thin structures – extend @ right angles from dento-enamel junction

Question 7

What is surrounding each rod?

Area btw the rods?

Answer 7

protein matrix of enamelin
interrod enamel (interrod cement)

Question 8

Pores

Answer 8

Minute spaces where crystals don’t form btw rods, contribute to enamel’s permeability

Question 9

if pH drops below 5.5 what happens?

Answer 9

demineralization & crystalline structure shrinks in size while pores enlarge

Question 10

Ameloblasts do what to enamel?

Answer 10

Enamel gets broken down removing enamels ability to regenerate/repair itself – cannot be restored beyond normal course of remineralization

Question 11

The tooth at eruption is

Answer 11

Not fully mineralized, complete mineralization with Ca & P & Fluoride ions from saliva by adding a layer of enamel

Question 12

Genetic disorder: Amelogenesis imperfecta is?

Answer 12

Enamel is never completely mineralized & flakes off exposing softer dentin to cariogenic bacteria. Other conditions linked like GERD and Celiac disease

Question 13

Dentin Structure

Answer 13

dentin is hard, light yellow, porous layer of tissue under enamel & cementum – is largest portion of the tooth

Question 14

What is Dentin made of

Answer 14

Ca & P ions form hydroxyapatite crystals that are 30x smaller & softer than enamel

Question 15

Dentin is a

Answer 15

Living tissue and can repair/regrow – tiny dentinal tubules running btw cementoenamel junction & pulp layer assist in regeneration

Question 16

What is in the dentin to remineralize it and to feel pain?

Answer 16

Cell processes in pulp layer extend into tubules creating new dentin & mineralizing it, n. pass through these dentinal tubules allowing dentin to transmit pain (unlike enamel)

Question 17

Pulp Chamber

Answer 17

Soft tissue, containing – coronal pulp w/n crown continuous w/ radicular pulp w/n root

• Pulp contains odontoblasts (creation of dentin) – contains neurons, vascular tissues, fibroblasts, and macrophages BUT doesn’t contain true lymphatic vessels
• Apical foramen @ end of radicular pulp

Question 18

Cementum

Answer 18

thin, light yellow layer of bone-like tissue covering root of teeth – anchor
teeth to bony walls of the tooth’s socket in periodontium by attaching to periodontal ligament

Question 19

What is the Cementum made of? and where is it?

Answer 19

Mainly Ca salts, joins enamel @ cervix of tooth @ cementoenamel junction in a sharp line (cementum overlaps enamel for a short distance)

Question 20

Saliva

Answer 20

Mixture of mucous & serious fluid, bodily fluids that are pale yellow, transparent, and benign in nature, secreted from salivary glands

Question 21

Parotid gland

Answer 21

largest pair of glands, parotid facial space, posterior to mandibular ramus, anterior & inferior to ear – secretes saliva through Stensen’s ducts to facilitate
mastication & swallowing

Question 22

Submandibular glands

Answer 22

pair of glands located beneath lower jaws – smaller than parotid,
they produce 70% of saliva via Wharton’s ducts

Question 23

Both parotid & submandibular glands secrete true saliva

Answer 23

(combo of serious fluid & mucous) also have acini connected to intercalated ducts that connect to striated ducts that have capacity to modify the mineral content of saliva

Question 24

Sublingual glands

Answer 24

located beneath tongue – secrete mainly mucous & does NOT have striated ducts, releasing mucous directly from acini via excretory ducts

Question 25

How many salivary glands are there?

Answer 25

Over 600 minor salivary glands found in all parts of oral mucosa except for gingival tissue & anterior hard palate
- Number of acini connected in tiny lobules and may have own excretory duct or share one w/ another minor gland

Question 26

Parasympathetic

Answer 26

Favors serous secretion and occurs via Cranial n. w/ glossopharyngeal n. innervating parotid & facial innervating submandibular/sublingual glands
• Release neurotransmitters that bind to receptors on acinar & ductal cells of salivary glands

Question 27

Direct Sympathetic

Answer 27

Favors viscous (mucoid) secretion via preganglionic n. in thoracic segment of spinal cord which synapse w/ postganglionic neurons – release neurotransmitter norepinephrine that binds to receptors on salivary gland acinar & ductal cells

Question 28

Indirect Sympathetic

Answer 28

stimulation of salivary glands via blood vessels that supply the glands innervation

Question 29

Both types of innervations

Answer 29

binding neurotransmitters to salivary gland receptors & increase in intracellular Ca & alterations in mem permeability

Question 30

Physical protective qualities

Answer 30

-Water content & water flow rate, saliva physically cleanses oral cavity of food & debris
-0.5-1L of saliva per day w/ 90% secreted from major glands – also dilutes & removes
organic acids from dental plaque

Question 31

Chemical Protective Qualities

Answer 31

• Contains # of electrolytes & organic molecules that minimize decreases in local pH, favors remineralization, sodium bicarbonate & P w/ other salivary components act as buffers/neutralizing agents in saliva
• Sialin tends to raise salivary pH to neutral levels
• Supersaturated w/ hydroxyapatite, fluorapatite, Ca, and P all in saliva compared to carbonated hydroxyapatite in enamel
• Supersaturated maintained by proline-rich proteins & statherins in saliva – increases likelihood of remineralization

Question 32

Antibacterial properties

Answer 32

o Mucins sulfated glycoproteins that trap, aggregate, and clear bacteria
o Enzymes amylase break down food particles that stick to teeth reducing bacterial build- up that can lead to decay

Question 33

Lysozyme

Answer 33

cationic protein lyses cell walls bacteria & inactive

Question 34

Lactoferrin

Answer 34

iron-binding glycoprotein that derives bacteria of energy & cannot
survive

Question 35

Peroxidase

Answer 35

protein forms free radical compounds in bacterial cells which cause them to self-destruct – immunoglobulins are antigen-binding proteins that block the adherence of bacteria to tooth surface and/or promote clearance of bacteria

Question 36

Immune Response

Answer 36

non-specific (innate) and specific (adaptive) factors including immunoglobulins that increase in # when exposed to cariogenic bacteria

Question 37

Secretory Immunoglobulin A (sIgA)

Answer 37

dominant immunoglobulin in healthy mouth – produced by gland-associated immunocytes scattered in acini & in clusters adjacent to
salivary duct

Question 38

Immunoglobulin G (IgG)

Answer 38

almost entirely derived from gingival crevicular fluid (blood exudate) that emerges from cervice btw gingiva and tooth – produced by plasma in
periodontal pockets