510-9

Question 1

Define: Distal, Mesial, Labial, Buccal, Facial, Lingual

Answer 1

Toward: Molars, Incisors, Lips, Cheeks, (lips + cheek), Tongue

Question 2

Define Occlusal

Answer 2

Top of a tooth - portion that touches another tooth.

Question 3

The organic material in enamel is composed of what and comprises what percentage of overall composite?

Answer 3

Type I collagen / Comprises only 0.5% of enamel.

Question 4

What is the main component of enamel?

Answer 4

Hydroxyapatite (Calcium Phosphate Hydroxide)

Ca10(PO4)6(OH)2

Question 5

What can too much Fluoride cause?

Answer 5

Fluorosis. It can interfere with normal enamel production and create divots on the surface of teeth creating a mottled look.

Question 6

Why do different acids produce different textures on enamel.

Answer 6

Orientation of crystals to the acid will erode some parts of enamel preferentially.

Question 7

Is the Dentinoenamel Junction (DEJ) smooth?

Answer 7

No. It is jagged and resists shearing forces.

Question 8

What are 3 types of enamel defects?

Answer 8

Enamel Lammela (dark lines running all the way through enamel)
Tufts (smaller crack-like formations close to the DEJ
Spindles (small radiating imperfections at the DEJ)

Question 9

What does the odontoblast process connect?

Answer 9

The Odontoblast to the DEJ

Question 10

What substance makes up most of the tooth?

Answer 10

Primary Dentin

Question 11

What are the 2 types of tertiary dentin?

Answer 11

Reactionary (laid down by existing odontoblasts)

Reparative (laid down by newly differentiated odontoblasts)

Question 12

What type of fibrils surround a developing odontoblast process?

Answer 12

Type I collagen fibrils.

Question 13

What can lead to a dead dentinal tract?

Answer 13

Odontoblast death

Question 14

Where is the Dentin-Pulp complex innervated?

Answer 14

By nerve loops that travel into the predentin originating in the Nerve plexus of Raschkow.

Question 15

What is one problem with direct innervation theory.

Answer 15

Before Raschkow and loops develop in teeth they can already feel pain.

Question 16

What’s a problem with Odontoblast as receptor theory?

Answer 16

In Vivo measurements suggest membrane potentials cannot propagate a neural signal.

Question 17

What is the best theory of dentin sensitivity?

Answer 17

Hydrodynamic model suggests droplets oozing out of dentin after exposure “pull” (via tubules) on Plexus of Raschkow and surrounding innervations.

Question 18

In composition cementum is most similar to:

Answer 18

Bone

Question 19

What is the most important type of cementum?

Answer 19

Anchorage cementum. This is acellular and has extrinsic fibers.

Question 20

Where are cellular and acellular cementum located?

Answer 20

Cellular is at the root of the tooth and has a role in repair and movement.

Acellular is above and serves as an attachment to the dentin.

Question 21

Describe AEFC vs CIFC

Answer 21

acellular extrinsic fiber cementum - no nuclei

cellular intrinsic fiber cementum - nuclei

Question 22

What is the principle tissue for tooth attachment?

Answer 22

Acellular Extrinsic Fiber Cementum

this is called extrinsic because the attaching fibers come mainly from the fibroblasts of the periodontal ligament

Question 23

Where is cellular intrinsic fiber cementum found?

Answer 23

pre-molars and molars

involved in repair

Question 24

Is abutment or overlap the most common type of cementoenamel junction.

Answer 24

Overlap (60%)

10% cases have too little cementum @ junction

Question 25

What are the 4 zones of the pulp?

Answer 25

Odontoblast zone, Cell-free zone of Weil, cell rich (fibroblast) zone, pulp core (nerve and vascular zone)

Question 26

What is the difference between the anatomical crown and clinical crown?

Answer 26

Entire enameled portion of tooth vs. exposed enameled portion of tooth above the gingiva.