16b dentin-pulp complex

what is the structural axis of the tooth

Dentin

SUMMARY OF GENERAL DENTINOGENESIS

Done

What is the crown covered by

Enamel

What is the root covered by

Cementum

What is the internal core of the tooth

Pulp

What is the largest volume of the teeth

(Mineralised tissue) dentin

What colour does dentin make the teeth

Yellowish

What aspect of dentin gives a yellowish colour

Mineralisation

What colour are primary teeth

White-blue

What makes the pulp turn grey

Pulp vitality - pulp becomes devitalised

Devitalised pulp meaning

Cell death of soft tissue of pulp which contains nerves, blood vesssels and connective tissues

What causes endodogenous pigmentation

Haemoglobin and drugs

What kind of pigmentation do haemoglobin and drugs cause

Endodogenous

What causes exogenous pigmentation

Amalgam

Which is more translucent: dentin or enamel

Enamel

What determines hardness 😉

Mineralisation

Which is harder 😛: dentin or enamel

Enamel

Is dentin harder than bone

Yes

How can dentin hardness vary

• between tooth types

• Between crown and root dentin

What determines radiolucency

Mineral content

Which is more radiolucent: enamel or dentin

Enamel

Which is more radiolucent: cementum or bone or dentin

Dentin

Cementum and bone are the least

Look

Done

In radiography is enamel darker than enamel

No its lighter

Is dentin darker than non-mineralised pulp

No its ligghter

Is permeability better in dentin or enamel

Dentin

Whats allows permeability to be better in dentin

Dentinal tubules

What is transport in dentin by

Difffusion

Or pressure of interstitial pulp fluids

What type of movement is there from pulp or DEJ

Fluid movement

What system does dentins permeability have

Biomaterial adhesion system

why is biomaterial adhesion system significant

Seals dentin and prevents fluid from entering with adhesion

How can fluid movement in the dentinal tubules

Outwards from pulp to DEJ

Inwards from DEJ to pulp

Which is more elastic enamel or dentin

Dentin

Why does dentin need to be elasic

Absorption of masticatory impacts

What causes elasticity in dentin to vary

Percentage of water and organic substance

What is the inorganic component that is 70% of dentin

Hydroxyapatite crystals

Are the hydroxyapatite smaller or larger than enamel

Smaller

Other than Hy. Crystals what other inorganic compounds are there

Amorphous phosphates, carbonates, fluoride, copper, zinc

What percentage of dentin are organic compounds

18%

What makes up 90% of organic components

Collagen fibers

What type of collagen is 98% of it

Tpye 1

What is the 10% of organic components that isnt collagen

Glycoproteins

What does the acronym SIBLING stand for

Small integrin-binding ligand n-liked glycoproteins

What type of proteins are SIBLINGs

Phosphorylated matrix proteins

What are SIBLINGs used for

Regulation

Calcification

Mineralisation

Of dentin and predentin

Examples of SIBLINGs

DSPP

DMP-1

DSP

DPP

What are SIBLINGs secreted by

Mature odontoblasts

What is osteopontin

Example of phosphorylated matrix proteins

What is the acronym of osteopontin

OPN

2 examples of NONphosphorylated matrix proteins

Osteocalcin

Osteonectin

What is 12% of dentin

(Other inorganic and organic compounds)

Water

PRIMARY DENTIN AND ITS STRUCTURAL UNITS

(DIVIDER SLIDE)

Type done

GO TO FLASHCARD 127 FOR SECONDARY STRUCTURE UNIT OF DENTIN

Done

When is primary dentin formed

Initial tooth development before root completion

When is secondary dentin formed

Formed after the root is completed

How are dentinal tubules arranged in relation to pulp or DEJ or CDJ

Run perpendicular all along the dentin

Look how its perpendicular

Done

What 2 things go inside dentinal tubules

Odontoblastic processes and dentinal fluid

What 2 things do dentinal tubules allow

Diffusion

Signals

What kind of primary curvature do the Dentinal tubules in the crown have

Double curve (like an S)

What kind of primary curvature do the Dentinal tubules in the Cusps have

None, they are straight

What kind of primary curvature do the Dentinal tubules in the Root have

1 slight curvature

Look primary curvatures of dentinal tubules

Done

What causes curvatures in the dentinal tubules

Crowding of odontoblasts as they move toward the center of pulp

What is the common shape of the secondary curvatures of the dentinal tubules

Wavy Sigmoidal shape

What is the common shape of the secondary curvatures of the dentinal tubules

Wavy Sigmoidal shape

What cuases the constant wave of secondary curvature of dentinal tubules

Odontoblast rotation during migration

Does the diameter of dentinal tubules increase or decrease with age

Decrease

what are megatubules

Much larger in diameter

(You dont have trypophobia do you????)

Where are megatubules found

In the pulp horns of the coronal dentin

What are lateral branches of dentinal tubules

Secondary tubules

What can secondary tubules act as

Connecting tubules

What do terminal tubules look like in crowns

Branch shaped

Where do terminal crown branches of tubules end

DEJ

What do branches of tubules look like in the root

Dichotomic

Where do terminal root branches of tubules end at

CDJ

What are odontoblastic processes that extend into DEJ called

Enamel spindles

Look

Done

what do you call the dentin matrix that surrounds the dentinal tubules lumen

Peritubular dentin / intratubular dentin

What is peritubular dentin also known as

IntRAtubular dentin

What do you call the dentin matrix that is between the dentinal tubules

Intertubular dentin

Look

Done

Is Intertubular dentin collagen rich or poor

Collagen rich

Is peritubular dentin collagen rich

No, it is collagen poor

Is peritubular dentin more mineralised than intertubular dentin

Yes

What is peritubular described as in comparison to intertubular

Highly mineralised

Collagen poor

When is peritubular dentin produced

When intertubular dentin mineralisation is complete

Where does peritubular dentin deposition start

Starts on the outside

Where does peritubular dentin deposition end

Ends in the center of the tubule

Where is peritubular dentin thinner

Closer to the pulp

Where is peritubular dentin thickest

Closer to the DEJ

Does peritubular dentin have a high composition of non-collagen proteins

Yes

(It is collagen poor)

Does peritubular dentin have a lot of hydroxyapatite crystals

Yes

how many layers does the peritubular dentin have

5

What is the 1st (most central) layer of the peritubular dentin

Odontoblastic process

What is the 2nd layer of the peritubular dentin

Periodontoblastic space

What is the 3rd (middle) layer of the peritubular dentin

Hypomineralised inner layer

What is the 4th layer of the peritubular dentin

Hypermineralised middle layer

What is the 5th (outermost) layer of the peritubular dentin

Hypomineralised outer layer

Look

Done

What gradually reduces the tubules diameter

Peritubular dentin formation