-
Enamel develops from which of the following embryonic tissues?
ectoderm
ectomesenchyme
mesoderm
endoderm
Both ectoderm and ectomesenchyme
Both ectomesenchyme and mesoderm
ectoderm
-
After the ameloblasts are finished with both enamel apposition and maturation, they become part of the reduced enamel
[Blank].
epithelium
-
Enamel matrix is first formed in the _____ part of the tooth near the forming DEJ.
incisal/occlusal
-
Enamel _____ are the crystalline structural unit of enamel.
rods
-
Enamel matrix is produced by the ___ cells.
ameloblast
-
Which of the following describes a pronounced band due to the trauma of birth present on the cross section of both enamel and dentin?
line of Retzius
imbrication line of von Ebner
neonatal line
contour line of Owen
perikymata
neonatal line
-
Which of the following cell types is NOT renewable during the lifetime of the tooth?
ameloblasts
odontoblasts
odontoclasts
cementoblasts
ameloblasts
-
What is the chemical formula for the
crystalline structure of mature enamel?
Ca12(PO4)6(OH)2
Ca10(PO5)5(OH)2
Ca8(PO5)2(OH)2
Ca10(PO4)6(OH)2
Ca10(PO4)6(OH)2
-
The crystalline structural unit of enamel, is cylindrical in longitudinal section with an average diameter of:
25 microns
4 microns
0.25 millimeter
1 micron
4 microns
-
Demineralization of the enamel occurs when the oral pH is less than:
5.5
6.0
6.5
7.0
5.5
-
In the fissures on the occlusal surfaces of teeth, the rods of the enamel are oriented so their positon is approximately:
Parallel to the DEJ
Perpendicualr to the walls of the fissure
Perpendicular to the DEJ
Circular, around the curvature of the fissure and parallel to its exposed surface
Perpendicualr to the walls of the fissure
-
Match the following terms with their descriptors:
Lines of Retzius
perikymata
neonatal line
imbrication lines
accentuated increment lines in enamel due to trauma of birth
incremental lines associated with the cyclical secretion of enamel
the raised scale like pattern of the outer enamel layer
the grooves between the scale like of the outer enamel layer
incremental lines associated with the cyclical secretion of enamel
the grooves between the scale like of the outer enamel layer
accentuated increment lines in enamel due to trauma of birth
the raised scale like pattern of the outer enamel layer
-
In the following microscopic view of a transverse section of tooth enamel, the white arrow is indicating what feature of mature enamel _____ ?
The black arrow is pointing to what other feature of mature enamel ___ ?
(figure 12-11 in text)
- enamel tufts
- enamel Lamella
-
The Hunter-Schreger light to dark bands seen in certain sections of enamel, as seen under a microscope by reflected light, are a result of:
Branching of dentinal tubles
Enamel rods bending to the right or left at a slightly different angle to adjacent enamel rod groups
A nutritional deficiency during the period of tooth development
Hypercalcification of the interprismatic region between the enamel rods
Enamel rods bending to the right or left at a slightly different angle to adjacent enamel rod groups
-
[Blank] is the loss of enamel due to tooth to tooth contact associated with mastication or parafunctional habits.
attrition
-
Enamel lost through
demineralization/decalcification caused by the waste products of cariogenic bacteria, is defined as [Blank].
caries
-
[Blank] is the loss of enamel caused by excessive contact with some sort of non-tooth structure such as a toothbrush, abrasive toothpaste, or hair/bobby pins.
abrasion
-
Enamel lost in deep narrow "V" shaped notches in the cervical areas of a tooth or teeth, as a result of excessive tensile and compressive forces associated with
parafunctional habits is defined as [Blank].
abfraction
-
When enamel is lost through chemical means (usually acid, not involving bacteria) this condition is defined as [Blank].
erosion
-
Acid etching is a dental procedure intended to chemicaly remove organic portions in the interprismatic regions of enamel to open gaps for sealant material to flow into and adhere to the tooth surface with a [Blank] attachment or bond.
microscopic mechanical
-
The area of tooth enamel where most stain collects and therefore is the area where whitening or bleaching of the teeth is most active is the:
Enamel rods
Interprismatic regions
Perikymata
Enamel spindles
Interprismatic regions
-
MORE THAN ONE ANSWER
The use of systemic and topical fluorides contribute to the increased caries resistance of tooth enamel by which of the following actions:
Covering the deepened pit and groove patterns on the occlusal surfaces of teeth
Altering the morphology of teeth
Directly remineralizing enamel
Interferring with the microbial production of acids
- Altering the morphology of teeth
- Directly remineralizing enamel
- Interferring with the microbial production of acids
-
Why should dental care NOT be based upon perceptions of dental pain?
Furthermore, what armamentatium should dental professionals employ in their attempts to both prevent and diagnose dental caries?
- If you have caries in only the enamel it doesn't cause pain because the enamel has no nerves within it. The pain only occurs when the deep layers of dentin and the pulp
- tissue are involved. The dental professional should emphasize the importance of follow up visits due to the above reason. Decay can be
- caught early before the pain develops and more damage is done.
|
|
