Transcript 13 Dentin 2

Oral Histology, Embryology & Genetics
Dent 5315/DH2215 February 19, 2008
Embryology in The News
Dentinogenesis - The Formation of Dentin
A. Dentinogenesis
B. Root Formation
C. Dentin-Pulp Complex
D. Dentin Classification
E. Clinical Correlations
THE DENTIN-PULP COMPLEX
“Origins”
THE DENTIN-PULP COMPLEX
Dentin and pulp are
related:
a. embryologically
histologically
functionally
b.
c.
dental papilla/pulp
THE DENTIN-PULP COMPLEX
THE DENTIN-PULP COMPLEX
Mature dentin-pulp complex
Note vascularity of pulp
“Subodontoblastic plexus of
Raschkow” occupies cell-free
zone of Weil (crown only)
THE DENTIN-PULP COMPLEX
Note:
dentin tubules &
odontoblastic
processes
b. irregular
mineralization
fronts (arrows)
a.
DENTIN CLASSIFICATION
Types of dentin:
globular/interglobular
DENTIN CLASSIFICATION
Types of dentin:
Interglobular dentin is especially
noticeable in vitamin D
deficiency, high levels of
fluoride, etc..
DENTIN CLASSIFICATION
Junction of primary
& secondary dentin.
DENTIN CLASSIFICATION
Types of dentin:
DENTIN CLASSIFICATION
Types of dentin:
reparative/tertiary dentin
What can initiate this
type of dentin?
Exposed open tubules,
caries, restorations,
chemicals such as
etching, etc.
ENAMEL vs DENTIN
Types of dentin:
reparative/tertiary
dentin
Note “S-shaped”
tubules in coronal
region
&
“dead tracts”
DENTIN CLASSIFICATION
Why does this tooth
appear pink?
Typical
radiographic
appearance of
internal root
(dentin)
resorption.
DENTIN CLASSIFICATION
Internal resorption with root
perforation (arrow)
dentin tubules
“giant cells”
DENTIN CLASSIFICATION
Area of normal tubular
dentin (arrow) & area
osteodentin.
Note multinucleated giant
cells resorbing both
calcified reparative tissue
& primary dentin.
DENTIN CLASSIFICATION
Types of dentin:
inter & intra
globular dentin
Inter = between
Intra = within
DENTIN CLASSIFICATION
Types of dentin:
sclerotic/transparent
dentin
www.kck.usm.my/ppsg/histology/ Histopathology_of_dental_Dental_caries_1.ppt -
CLINICAL CORRELATIONS
1. How does a knowledge
of dentin affect cavity
preparation?
a. amputation of
odontoblastic
processes
b. communication to
pulp
c. placement of bases,
pulp injury (heat, acid
etch, etc.)
d. progression of caries
bacteria
Cavity preparation in dentin
CLINICAL CORRELATIONS
“Rampant”
Caries
Note areas of
demineralization
Clinical Correlations
2. What makes dentin
structure susceptible
to caries?
A. Dentin has a tubular
structure.
B. Caries can spread along
DEJ.
C. Crystals dissolve at low
pH produced by
cariogenic bacteria.
CLINICAL CORRELATIONS
Horizontal clefting right
angle to dentinal
tubules.
Bacterial beading,
coalescence, clefting
typifies progression of
dentinal caries.
CLINICAL CORRELATIONS
3. What is dentin
hypersensitivity? Why
is dentin sensitive?
Pain due to communication
between outside
environment & pulp.
3 Theories of dentin
hypersensitivity. (Fig. 8-61)
CLINICAL CORRELATIONS
Dentin hypersensitivity
Loose/defective restoration
Dessication forces
CLINICAL CORRELATIONS
Product
Evaluation