DH 306 Exam 3
1. Is enamel vascular or avascular?: avascular
2. Does enamel have nerves?: No
3. What dental tissue is nonvital but not static?: Enamel
4. What is the hardest calcified tissue in the body?: Enamel
5. What percent inorganic material is in enamel?: 96%
6. What percent of organic material is in enamel?: 1%
7. What percent water is in enamel?: 3%
8. What major mineral compound is in enamel?: Calcium hydroxyapatite
9. Ca10(PO4)6(OH)2: calcium hydroxyapatite
10.Is enamel more radiopaque than dentin and pulp?: Yes
11.What is enamel matrix formation called?: Amelogenesis
12.What is enamel matrix produced by?: Ameloblasts
13.Where do ameloblasts originate from?: IEE
14.What secretory surface secretes enamel matrix?: Tomes' process
15.Does enamel matrix differentiate in the root area?: NO
16.Why doesn't enamel differentiate in the root area?: Due to loss of stellate reticulum and stratum
intermedium
17.What process is ectodermal in origin?: Tomes' process
, DH 306 Exam 3
18.Tomes' process is derived from what enamel epithelium?: IEE
19.In enamel apposition, what do ameloblasts do?: Actively transport materials into partially mineralized enamel
20.SMALL amounts of calcium hydroxyapatite crystals are pumped directly into the enamel matrix by what
process?: Tomes; Process
21.Enamel matrix is first formed in what part of the tooth?: incisal/occlusal (future portion of crown near
DEJ)
22.What direction does the enamel apposition process move?: Cervically
23.When enamel is matured, ameloblasts become part of what enamel epithe- lium?: REE
24.What is the REE?: Reduced enamel epithelium: compressed enamel organ
25.The REE peels away from the erupting tooth, and becomes the future
: Junctional Epithelium
26.Do odontoblasts sit in pulp or dentin?: Pulp
27.Once the REE peels away from the erupting tooth, what happens to the ameloblasts?: They disintegrate
28.What minerals from the saliva help in mineralization?: Fl2 and Ca2
29.What bands are alternating light and dark?: Hunter-Shreger Bands
30.What bands can be seen with reflected light?: Hunter- Shreger Bands
31.What bands are related to the curvature of enamel rods?: Hunter- Shreger Bands
, DH 306 Exam 3
32.What are the surrounding rods of enamel called?: Interprismatic region
33.What junction is scalloped?: Dentinoenamel junction (DEJ)
34.Is the concave side of the DEJ toward the enamel or dentin?: Enamel
35.Is the convex side of the DEJ toward the enamel or dentin?: Dentin
36.What was formerly the basement membrane between the enamel organ and the dental papilla?: DEJ
37.What is the function of the DEJ?: Allows for increased strength of the junction when teeth are in masticatory
function
38.What does Gnarled enamel under cusps look like?: Wavy appearance of enamel under cusps
39.What is the function of gnarled enamel under cusps?: Confers strength to enamel in areas of high occlusal
force
40.What is the rhythmic deposition of enamel called that looks like incremen- tal lines?: Lines of Retzius
41.What does each band in enamel represent?: work/rest period
42.Imbrication lines and grooves of perikymata are associated with what?: -
Lines of Retzius
43.Where are imbrication lines and grooves of perikymata found?: non-masti- catory surface of some teeth (max.
central incisors, canines, first premolars)
44.What is the accentuated incremental line of Retzius called?: Neonatal line
45.What is the significance of the neonatal line?: Marks the stress/trauma experienced by ameloblasts during
birth
1. Is enamel vascular or avascular?: avascular
2. Does enamel have nerves?: No
3. What dental tissue is nonvital but not static?: Enamel
4. What is the hardest calcified tissue in the body?: Enamel
5. What percent inorganic material is in enamel?: 96%
6. What percent of organic material is in enamel?: 1%
7. What percent water is in enamel?: 3%
8. What major mineral compound is in enamel?: Calcium hydroxyapatite
9. Ca10(PO4)6(OH)2: calcium hydroxyapatite
10.Is enamel more radiopaque than dentin and pulp?: Yes
11.What is enamel matrix formation called?: Amelogenesis
12.What is enamel matrix produced by?: Ameloblasts
13.Where do ameloblasts originate from?: IEE
14.What secretory surface secretes enamel matrix?: Tomes' process
15.Does enamel matrix differentiate in the root area?: NO
16.Why doesn't enamel differentiate in the root area?: Due to loss of stellate reticulum and stratum
intermedium
17.What process is ectodermal in origin?: Tomes' process
, DH 306 Exam 3
18.Tomes' process is derived from what enamel epithelium?: IEE
19.In enamel apposition, what do ameloblasts do?: Actively transport materials into partially mineralized enamel
20.SMALL amounts of calcium hydroxyapatite crystals are pumped directly into the enamel matrix by what
process?: Tomes; Process
21.Enamel matrix is first formed in what part of the tooth?: incisal/occlusal (future portion of crown near
DEJ)
22.What direction does the enamel apposition process move?: Cervically
23.When enamel is matured, ameloblasts become part of what enamel epithe- lium?: REE
24.What is the REE?: Reduced enamel epithelium: compressed enamel organ
25.The REE peels away from the erupting tooth, and becomes the future
: Junctional Epithelium
26.Do odontoblasts sit in pulp or dentin?: Pulp
27.Once the REE peels away from the erupting tooth, what happens to the ameloblasts?: They disintegrate
28.What minerals from the saliva help in mineralization?: Fl2 and Ca2
29.What bands are alternating light and dark?: Hunter-Shreger Bands
30.What bands can be seen with reflected light?: Hunter- Shreger Bands
31.What bands are related to the curvature of enamel rods?: Hunter- Shreger Bands
, DH 306 Exam 3
32.What are the surrounding rods of enamel called?: Interprismatic region
33.What junction is scalloped?: Dentinoenamel junction (DEJ)
34.Is the concave side of the DEJ toward the enamel or dentin?: Enamel
35.Is the convex side of the DEJ toward the enamel or dentin?: Dentin
36.What was formerly the basement membrane between the enamel organ and the dental papilla?: DEJ
37.What is the function of the DEJ?: Allows for increased strength of the junction when teeth are in masticatory
function
38.What does Gnarled enamel under cusps look like?: Wavy appearance of enamel under cusps
39.What is the function of gnarled enamel under cusps?: Confers strength to enamel in areas of high occlusal
force
40.What is the rhythmic deposition of enamel called that looks like incremen- tal lines?: Lines of Retzius
41.What does each band in enamel represent?: work/rest period
42.Imbrication lines and grooves of perikymata are associated with what?: -
Lines of Retzius
43.Where are imbrication lines and grooves of perikymata found?: non-masti- catory surface of some teeth (max.
central incisors, canines, first premolars)
44.What is the accentuated incremental line of Retzius called?: Neonatal line
45.What is the significance of the neonatal line?: Marks the stress/trauma experienced by ameloblasts during
birth
