Dental Unit

Question 1

periodontium

Answer 1

tissues supporting the tooth

made up of cementum,pdl,bone all protected by gingiva

Question 2

Cementum

Answer 2

is a hard,avascular connective tissue that covers the root of the teeth

Question 3

2 MAIN forms of Cementum

and their meanings

Answer 3

Acellular for ATTACHMENT of tooth

Cellular for REPAIR of periodontal tissues

Question 4

what is predominant collagen of cementum.

and its main function (3)

Answer 4

TYPE 1 collagen

also major type in pdl area

mf: is to structure the fiber bundles and anchor teeth

distribute masticatory force

Question 5

alveolar process

Answer 5

bone of jaws that contain sockets of teeth

Question 6

alveolar crest

Answer 6

location where cortical plate and alveolar bone meet

Question 7

what is periodontal ligament?
where can it be found and its function?
thinnest around middle 3rd

Answer 7

a soft specialized connective tissue that can be found in between root covering cementum and the bone that forms socket walls

MF: Supporting teeth in sockets and allowing them to withstand masticatory force

acts as sensory receptor

Question 8

(8) cells that pdl consists of

Answer 8

Fibroblasts

ERMs

macrophages

undifferentiated mesenchymal cells

stem cells

cementoblasts

osteoblasts and osteoclast but they are functionally associated with the bone

Question 9

principal fiber bundles of pdl (5)

Answer 9

alevolar crest group

horizontal group

oblique group

apical group

interradicular group

Question 10

Sharpey’s fibre

Answer 10

end portions of pricpal fibre budles embedded into the cementum or bone

Question 11

Five groups of fibre bundles that make up gingival ligament

Answer 11

Dentogingival group
• Alveologingival group
• Circular group
• Dentoperiosteal group
• Transseptal fibre system

Question 12

Ground substance (70% water)
and function

Answer 12

amorphous background material which
binds tissues and fluids

has significant effect on the ability of a tooth to withstand stress loads

Question 13

deep sulcus

Answer 13

periodontal pocket

Question 14

cells responsible for enamel formation

Answer 14

ameloblasts

Question 15

physical characteristics of enamel (3)

Answer 15

translucent

colour varies depending on thickness

96% inorganic material

Question 16

Fundamental organizational units of enamel are

Answer 16

rods and inter rod enamel

cylindrical rods embedded
in inter rod enamel

Question 17

inter rod enamel

Answer 17

surronds each rod enamel and its crystals are orientedd in a different direction from those making up the rod

Question 18

amelogenesis

Answer 18

enamel formation

Question 19

3 stages of amelogenesis

Answer 19

inductive
secretory stage
maturation stage

Question 20

ameloblasts(3)

Answer 20

cells that make enamel

secrete matrix proteins
and
maintain a extracellular environment for mineral deposition

Question 21

what is Striae of Retzius and what they mean

in longitudinal section of a tooth

Answer 21

series
of lines made of enamel rods extending from the dentinoenamel junction towards
the tooth surface

are incremental growth lines

Question 22

neo-natal line

Answer 22

enlarged Stria of
Retzius, which apparently reflects the great physiologic
changes occurring at birth

Question 23

Hunter-Schreger bands

Answer 23

changes in direction between adjacent groups of rods

bands appear as dark and light alternating zones

Question 24

gnarled

enamel

Answer 24

over cusp tips

make rods appear twisted around each other

Question 25

Enamel tufts

Answer 25

project for a short distance into enamel from the dej appear to be branched contain lots of enamel proteins

Question 26

enamel lamellae

Answer 26

extending depth varies cracks in enamel

Question 27

dentinoenamel junction

Answer 27

crystals of dentine and enamel intermix

Question 28

amelogenesis imperfecta 3 dif classifications

Answer 28

a group of inhereted defects hypoplastic hypocalcified hypomature

Question 29

amelogeensis defects

Answer 29

febrile diseases tetracycline induced disturbances excess fluoride ion concentrations of 5ppm

Question 30

dentine

Answer 30

hard tissue portion of the pulp-dentine complex, and forms the bulk of the tooth. harder than bone softer than enamel 70% inorganic materail

Question 31

odontontoblasts

Answer 31

form and maintain dentine cell on the outerwall of dental pulps

Question 32

dental pulp

Answer 32

soft connective tissue that occupies the cen tral portion of the tooth

Question 33

apical foramen

Answer 33

meeting place of pulp and pdl main nerves and vessels enter and leave here

Question 34

3 dif stages of dentine formation after differentiation (3)

Answer 34

mantle primary secondary tertiary

Question 35

Dentinogenesis

Answer 35

formation of dentine done by odonto blasts begins at the late bell stage

Question 36

tertiary dentine

Answer 36

ONLY produced by cells directley affected by stimlus

Question 37

sub classifications of tertiary dentine | and their functions

Answer 37

REACTIONARY dentine deposited by exsisiting odontoblasts REPARATIVE dentine depostied by newly differentiated odontoblast-like cells

Question 38

scelerotic dentine

Answer 38

appears when tubules which have become filled with calcified material.

Question 39

dentinogenesis imperfecta

Answer 39

hereditary condition characterized by abnormal dentine formation

Question 40

dental pulp

Answer 40

soft connective tissue that supports dentine

Question 41

4 histological zones of dental pulp and location

Answer 41

the odontoblastic zone at the pulp periphery cell free zone of weil below odontoblasts cell rich zone has high density pulp core contains many vessels and nerves

Question 42

which cells make pulp and what to they form

Answer 42

fibroblasts and they are numerous in coronal pulp and form cell-rich zone

Question 43

plexus of | nerves in the cell-free zone of Weil in the crown of the tooth

Answer 43

subodontoblastic plexus of Raschkow

Question 44

hydrodynamic theory

Answer 44

fluid movement through the tubule distorts the local pulpal environment, and is sensed by the free nerve endings in the plexus of Raschkow

Question 45

4 classic functions of pulp

Answer 45

Formative: Produces the dentine that surrounds it. • Nutritive: Nourishes the avascular dentine. • Protective: Carries nerves that give dentine its sensitivity. • Reparative: Capable of producing new dentine as required.