Operative dentistry NBDE II Exam
2025 Questions and Answers
How thick is enamel usually - ANSWER✔✔-2-3mm
Where is enamel thickest - ANSWER✔✔-incisal/occlusal surface
What is the diameter of enamel rods - ANSWER✔✔-4-8 micrometers
The dentin tubules follow ____ course to the pulp and the tubules are interconnected
_____ - ANSWER✔✔-S, laterally
Primary Dentin - ANSWER✔✔-Dentin at tooth eruption to 3 years post eruption
Secondary Dentin - ANSWER✔✔-Regular dentin formed throughout life
Tertiary Dentin (also called what?) - ANSWER✔✔-Reparative Dentin: An atubular type
of dentin formed in response to irritation after the odontoblasts die
Dead Tracts - ANSWER✔✔-Empty tubules as a result of odontoblastic process
degeneration
,Sclerotic - ANSWER✔✔-The obliteration of dentin tubules by calcified material (not
well organized)
Dentin is ____% inorganic material and ___% organic material and water -
ANSWER✔✔-75, 25
What is indirect dentin pulp capping - ANSWER✔✔-Medically treating a very thin
layer of dentin without exposure of the pulp.
What is direct dentin pulp capping - ANSWER✔✔-Medically treating a very thin layer
of dentin with exposure of the pulp
What is a Dentin Smeared layer - ANSWER✔✔-An amorphous layer of tooth structure
and cutting debris "smeared" on the surface of the tooth after preparation.
What are the three types of pulp - ANSWER✔✔-coronal, radicular, and accessory
where is Coronal pulp - ANSWER✔✔-pulp chambers and pulp horns
Where is Radicular pulp - ANSWER✔✔-pulp canals and apical foramen
Where is accessory pulp - ANSWER✔✔-accessory canals
What are the 4 functions of pulp - ANSWER✔✔-formation (primary and secondary
dentin), nutritive, sensory/protection, and reparative/defensive
Cementum is composed of approximately __% organic and ___% inorganic material. -
ANSWER✔✔-50, 50
,What are the two types of cementum - ANSWER✔✔-acellular (coronal half) and cellular
(apical half)
What are the 4 embrasures - ANSWER✔✔-facial, lingual, incisal or occlusal, and
gingival
What are the 4 terms for extent of caries - ANSWER✔✔-incipient, cavitated, primary,
secondary
Cavitated caries - ANSWER✔✔-(lesions that have progressed to a more advanced stage.
Cavitation usually occurs because of external forces that eventually lead to the collapse
of the outer surface in a non-cavitated lesion, which in turn leads to a discontinuity or
break in the surface. The break in the surface may be limited to the enamel, or it may
expose the dentin. By this point, demineralization has usually progressed histologically,
radiographically, and/or clinically into the dentin, and bacteria can invade the dentin
and cause tissue infection. This stage of the disease generally requires operative
intervention to restore function and to help arrest the caries process inside the tooth).
Secondary Caries (recurrent): - ANSWER✔✔-Observed around the edges and UNDER
restorations- due to marginal leakage or inadequate extension of the restoration.
What are the two rates of caries - ANSWER✔✔-acute and chronic
What are the types of NON-CARIES tooth defects - ANSWER✔✔-Abrasion
Erosion
, Abfraction
Attrition
Fractures
Nonhereditary Enamel Hypoplasia
Amelogenesis Imperfecta
Dentinogenesis Imperfecta
What are the three types of tooth numbering systems - ANSWER✔✔-
Zsigmondy/Palmer system.
FDI system.
Universal system.
How does the Palmer System work and who uses it most - ANSWER✔✔-orthodontist:
Each quadrant starts at the central incisor and goes outward 1-8. The tooth that is being
referred to has a part of a box around it, depending on where the tooth is will determine
what sides of the box are present
Explain the FDI System - ANSWER✔✔-Same as Palmer as far as numbering, except
there is a 1, 2, 3, or 4 before the numbers to show quadrants
What are the types of walls/floors made in a cavity prep - ANSWER✔✔-Internal
preparation wall (Axial wall and Pulpal wall (floor))
2025 Questions and Answers
How thick is enamel usually - ANSWER✔✔-2-3mm
Where is enamel thickest - ANSWER✔✔-incisal/occlusal surface
What is the diameter of enamel rods - ANSWER✔✔-4-8 micrometers
The dentin tubules follow ____ course to the pulp and the tubules are interconnected
_____ - ANSWER✔✔-S, laterally
Primary Dentin - ANSWER✔✔-Dentin at tooth eruption to 3 years post eruption
Secondary Dentin - ANSWER✔✔-Regular dentin formed throughout life
Tertiary Dentin (also called what?) - ANSWER✔✔-Reparative Dentin: An atubular type
of dentin formed in response to irritation after the odontoblasts die
Dead Tracts - ANSWER✔✔-Empty tubules as a result of odontoblastic process
degeneration
,Sclerotic - ANSWER✔✔-The obliteration of dentin tubules by calcified material (not
well organized)
Dentin is ____% inorganic material and ___% organic material and water -
ANSWER✔✔-75, 25
What is indirect dentin pulp capping - ANSWER✔✔-Medically treating a very thin
layer of dentin without exposure of the pulp.
What is direct dentin pulp capping - ANSWER✔✔-Medically treating a very thin layer
of dentin with exposure of the pulp
What is a Dentin Smeared layer - ANSWER✔✔-An amorphous layer of tooth structure
and cutting debris "smeared" on the surface of the tooth after preparation.
What are the three types of pulp - ANSWER✔✔-coronal, radicular, and accessory
where is Coronal pulp - ANSWER✔✔-pulp chambers and pulp horns
Where is Radicular pulp - ANSWER✔✔-pulp canals and apical foramen
Where is accessory pulp - ANSWER✔✔-accessory canals
What are the 4 functions of pulp - ANSWER✔✔-formation (primary and secondary
dentin), nutritive, sensory/protection, and reparative/defensive
Cementum is composed of approximately __% organic and ___% inorganic material. -
ANSWER✔✔-50, 50
,What are the two types of cementum - ANSWER✔✔-acellular (coronal half) and cellular
(apical half)
What are the 4 embrasures - ANSWER✔✔-facial, lingual, incisal or occlusal, and
gingival
What are the 4 terms for extent of caries - ANSWER✔✔-incipient, cavitated, primary,
secondary
Cavitated caries - ANSWER✔✔-(lesions that have progressed to a more advanced stage.
Cavitation usually occurs because of external forces that eventually lead to the collapse
of the outer surface in a non-cavitated lesion, which in turn leads to a discontinuity or
break in the surface. The break in the surface may be limited to the enamel, or it may
expose the dentin. By this point, demineralization has usually progressed histologically,
radiographically, and/or clinically into the dentin, and bacteria can invade the dentin
and cause tissue infection. This stage of the disease generally requires operative
intervention to restore function and to help arrest the caries process inside the tooth).
Secondary Caries (recurrent): - ANSWER✔✔-Observed around the edges and UNDER
restorations- due to marginal leakage or inadequate extension of the restoration.
What are the two rates of caries - ANSWER✔✔-acute and chronic
What are the types of NON-CARIES tooth defects - ANSWER✔✔-Abrasion
Erosion
, Abfraction
Attrition
Fractures
Nonhereditary Enamel Hypoplasia
Amelogenesis Imperfecta
Dentinogenesis Imperfecta
What are the three types of tooth numbering systems - ANSWER✔✔-
Zsigmondy/Palmer system.
FDI system.
Universal system.
How does the Palmer System work and who uses it most - ANSWER✔✔-orthodontist:
Each quadrant starts at the central incisor and goes outward 1-8. The tooth that is being
referred to has a part of a box around it, depending on where the tooth is will determine
what sides of the box are present
Explain the FDI System - ANSWER✔✔-Same as Palmer as far as numbering, except
there is a 1, 2, 3, or 4 before the numbers to show quadrants
What are the types of walls/floors made in a cavity prep - ANSWER✔✔-Internal
preparation wall (Axial wall and Pulpal wall (floor))
