PPT 9 Teeth and Dental Tissues

Question 1

The part of the tooth covered by enamel is the ______ crown

Answer 1

anatomical

Question 2

The part of the tooth exposed above the gingiva is the _____ crown.

Answer 2

clinical

Question 3

The _____ attaches cementum of the roots to the alveolar bone.

Answer 3

Periodontal ligament (PDL)

Question 4

The hardest part of the human body
about 96% mineral
non-living tissue in adults

Answer 4

Enamel

Question 5

Second hardest material in the human body
about 70% mineral
living tissue in adults

Answer 5

Dentin

Question 6

Highly innervated and vascular loose connective tissue in the core of a tooth.

Answer 6

Pulp

Question 7

Living, bone-like tissue in adults that surrounds root

About 45-60% mineral

Answer 7

Cementum

Question 8

Enamel is about 96% _____, 0.5% _____ and the rest is _____.

Answer 8

mineral, organic material, water

Question 9

Most of the mineral in enamel is _______ and most of the organic material is _____.

Answer 9

calcium phosphate, type I collagen

Question 10

_____ are various chemical forms of calcium phosphate combined with either CL-, Fl- or OH- ions.

Answer 10

“Apatites”

i.e. Chloroapatite, fluoroapatite, hydroxyapatite.

Question 11

Enamel is composed predominantly of crystals of calcium phosphate in the form of _____.

Answer 11

hydroxyapatite

Question 12

Chronic ingestion of fluoride at concentrations higher than 5ppm interferes with enamel production and gives it a mottled appearance called _____.

Answer 12

Flurosis.

Question 13

Enamel meets dentin at the _____.

Answer 13

dentinoenamel junction (DEJ)

Question 14

All of the enamel is produced by cells called ______ as the tooth is developing.

Answer 14

ameloblasts

Question 15

_____ are linear defects that can span the full thickness of the enamel.

Answer 15

Enamel lamellae

Question 16

_____ project into the enamel a shorter distance from the dentinoenamel junction than the enamel lamellae.

Answer 16

Enamel tufts

Question 17

Before enamel forms, some odontoblast processes extend into the ameloblast epithelium and become trapped there as enamel begins to form. These trapped processes can become _____.

Answer 17

enamel spindles

Question 18

Structures that span the dentin and remain attached to the dentinoenamel junction from the odontoblasts are called _____.

Answer 18

odontoblast processes.

Question 19

Odontoblasts are nourished by blood vessels in the _____.

Answer 19

pulp

Question 20

_____ is newly deposited material that matures into dentin as it mineralizes.

Answer 20

Predentin

Question 21

_____ makes up most of the tooth and is the mineralized dentin.

Answer 21

Primary dentin

Question 22

_____ develops after the root formation is complete but proceeds very slowly, and gradually reduces the size of the pulp cavity.

Answer 22

Secondary dentin

Question 23

_____ is the dentin that forms under the enamel of the crown.

Answer 23

Mantle dentin

Question 24

_____ is produced locally in response to caries, attrition and dental restoration.

Answer 24

Tertiary dentin

Question 25

Two subclasses of tertiary dentin are _____ and _____.

Answer 25

reactionary dentin and reparative dentin.

Question 26

Dentin sensitivity is explained by the theory that _____

Answer 26

the tubular nature of dentin permits fluid movement to occur within the tubule when a stimulus is applied. A movement registered by pulpal free nerve endings close to the odontoblasts.

Question 27

What is wrong with the direct innervation theory?

Answer 27

Nerves only penetrate the dentin a short distance into the tubules.

Question 28

What is wrong with the odontoblast receptor theory?

Answer 28

The membrane potential of odontoblasts appears to be too small for sensory transduction.

Question 29

Cells that produce cemntum are initially called _____ and they look like fibroblasts.

Answer 29

cementoblasts

Question 30

Cementoblasts mature into dentritic _____ that are surrounded by cementum matrix. They look much like osteocytes.

Answer 30

cementocytes

Question 31

The two most important types of cementum are _____ and _____.

Answer 31

acellular and cellular

Question 32

Acellular cementum is made up of _____ fibers and covers the cervical magin to the apical third of the tooth.

Answer 32

extrinsic

Question 33

Cellular cementum is made up of _____ fibers and covers the middle to apical third of the tooth.

Answer 33

intrinsic

Question 34

At the dentin-cementum junction is thought to be a mix of collagen and non-collagenous matrix proteins at the interface between dentin and cementum known as _____.

Answer 34

The granular layer of Tomes (GLT)

Question 35

There are 3 configurations of the cementoenamel junction. 60% of cases the cementum _____ the enamel.
30% of cases the cementum _____ the enamel.
10% of cases the cementum is insufficient.

Answer 35

overlaps

abuts

Question 36

The principal cells of pulp are _____ and _____.

Answer 36

odontoblasts and fibroblasts

Question 37

The 4 zones of the pulp are:

Answer 37

1. Odontoblastic zone
2. Cell-free zone
3. Cell-rich zone
4. Pulp core