Dental Unit Flashcards
FLASHCARDS FOR Enamel Dentino-Pulpal Complex Periodontium
periodontium
tissues supporting the tooth
made up of cementum,pdl,bone all protected by gingiva
Cementum
is a hard,avascular connective tissue that covers the root of the teeth
2 MAIN forms of Cementum
and their meanings
Acellular for ATTACHMENT of tooth
Cellular for REPAIR of periodontal tissues
what is predominant collagen of cementum.
and its main function (3)
TYPE 1 collagen
also major type in pdl area
mf: is to structure the fiber bundles and anchor teeth
distribute masticatory force
alveolar process
bone of jaws that contain sockets of teeth
alveolar crest
location where cortical plate and alveolar bone meet
what is periodontal ligament?
where can it be found and its function?
thinnest around middle 3rd
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
(8) cells that pdl consists of
Fibroblasts
ERMs
macrophages
undifferentiated mesenchymal cells
stem cells
cementoblasts
osteoblasts and osteoclast but they are functionally associated with the bone
principal fiber bundles of pdl (5)
alevolar crest group
horizontal group
oblique group
apical group
interradicular group
Sharpey’s fibre
end portions of pricpal fibre budles embedded into the cementum or bone
Five groups of fibre bundles that make up gingival ligament
Dentogingival group • Alveologingival group • Circular group • Dentoperiosteal group • Transseptal fibre system
Ground substance (70% water) and function
amorphous background material which
binds tissues and fluids
has significant effect on the ability of a tooth to withstand stress loads
deep sulcus
periodontal pocket
cells responsible for enamel formation
ameloblasts
physical characteristics of enamel (3)
translucent
colour varies depending on thickness
96% inorganic material
Fundamental organizational units of enamel are
rods and inter rod enamel
cylindrical rods embedded
in inter rod enamel
inter rod enamel
surronds each rod enamel and its crystals are orientedd in a different direction from those making up the rod
amelogenesis
enamel formation
3 stages of amelogenesis
inductive
secretory stage
maturation stage
ameloblasts(3)
cells that make enamel
secrete matrix proteins
and
maintain a extracellular environment for mineral deposition
what is Striae of Retzius and what they mean
in longitudinal section of a tooth
series
of lines made of enamel rods extending from the dentinoenamel junction towards
the tooth surface
are incremental growth lines
neo-natal line
enlarged Stria of
Retzius, which apparently reflects the great physiologic
changes occurring at birth
Hunter-Schreger bands
changes in direction between adjacent groups of rods
bands appear as dark and light alternating zones
gnarled
enamel
over cusp tips
make rods appear twisted around each other
Enamel tufts
project for a short distance into enamel from the dej
appear to be branched
contain lots of enamel proteins
enamel lamellae
extending depth varies
cracks in enamel
dentinoenamel junction
crystals of dentine and enamel intermix
amelogenesis imperfecta
3 dif classifications
a group of inhereted defects
hypoplastic
hypocalcified
hypomature
amelogeensis defects
febrile diseases
tetracycline induced disturbances
excess fluoride ion concentrations of 5ppm
dentine
hard tissue portion of the pulp-dentine complex,
and forms the bulk of the tooth.
harder than bone softer than enamel
70% inorganic materail
odontontoblasts
form and maintain dentine
cell on the outerwall of dental pulps
dental pulp
soft connective tissue that occupies the
cen
tral portion of the tooth
apical foramen
meeting place of pulp and pdl
main nerves and vessels enter and leave here
3 dif stages of dentine formation after differentiation (3)
mantle
primary
secondary
tertiary
Dentinogenesis
formation of dentine done by odonto blasts
begins at the late bell stage
tertiary dentine
ONLY produced by cells directley affected by stimlus
sub classifications of tertiary dentine
and their functions
REACTIONARY dentine deposited by exsisiting odontoblasts
REPARATIVE dentine depostied by newly differentiated odontoblast-like cells
scelerotic dentine
appears
when tubules which have become
filled with calcified material.
dentinogenesis imperfecta
hereditary condition characterized by abnormal dentine formation
dental pulp
soft connective tissue that supports dentine
4 histological zones of dental pulp and location
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
which cells make pulp and what to they form
fibroblasts
and they are numerous in coronal pulp and form cell-rich zone
plexus of
nerves in the cell-free zone of Weil in the crown of the tooth
subodontoblastic plexus of Raschkow
hydrodynamic theory
fluid movement
through the tubule distorts the local pulpal environment, and
is sensed by the free nerve endings in the plexus of Raschkow
4 classic functions of pulp
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.
