NDAEB EXAM COMPREHENSIVE REVIEW 2026
QUESTIONS AND DETAILED SOLUTIONS
◉ What type of mixing surface is ZOE mixed? Answer: An oil-
resistant paper pad that will not absorb any of the liquid, or when a
slower set is required use a glass slab.
◉ How is TempBond supplied? Answer: Two-paste system.
◉ Zinc Phosphate cements: Answer: Type I (fine-grain): used for
permanent cementation of cast restorations. Creates a very thing
film layer.
Type II (medium-grain): recommended for use as an insulating
based for deep cavity preparations.
◉ What should zinc phosphate be mixed on? Answer: A cool, dry,
thick glass slab because of the exothermic reaction that occurs when
zinc phosphate is mixed.
◉ What is the main component in the liquid form of zinc phosphate?
Answer: phosphoric acid, which is the component that is irritating to
the pulp.
,◉ What are the 3 classifications of impressions taken in dental
procedures? Answer: Preliminary, final, and occlusal (otherwise
known as a bite registration).
◉ Is an impression a negative or positive reproduction? Answer:
Negative. & the model poured is a positive reproduction.
◉ When selecting a stock tray for impressions, what must you look
for? Answer: - Patient comfort.
- Extends slightly beyond the facial surface of the teeth.
- Extends 2-3mm beyond the third molar, retromolar, or tuberosity
area of the arch.
- Sufficiently deep to allow 2-3mm of material between the tray and
incisal or occlusal edges of teeth.
◉ What type of wax is used when a tray needs to be extended or
more depth created? Answer: Utility wax.
◉ Which type of impression tray covers half of an arch? Answer:
Section trays.
◉ What are the main components of alginate? Answer: Potassium
alginate - derived from seaweed, used as a thickening agent.
Calcium sulfate - reacts with ^ to form the gel.
,Trisodium phosphate - slows down reaction for mixing.
Diatomaceous Earth - filler. adds bulk.
Zinc oxide - adds bulk.
Potassium titanium fluoride - prevents interference with the setting
and surface strength of the product.
◉ What is the name for the condition when alginate absorbs
additional water and expands? Answer: Imbibition.
◉ What is the name for the condition when moisture evaporates
from the material causing it to shrink? Answer: Syneresis.
◉ What types of setting does alginate come in? Answer: Normal set
& fast set.
◉ What does 'working time' refer to? Answer: The time allowed for
mixing the alginate, loading the tray, and positioning the tray in the
pt's mouth.
◉ What does 'setting time' refer to? Answer: The time required for
the chemical action to be complete, after which the impression is
ready or be removed from the patients mouth.
, ◉ What specific criteria must an acceptable alginate impression
meet? Answer: - Tray should be centered.
- A complete 'peripheral roll'
- Tray is not overseated.
- Impression is free from tears or voids.
- Sharp anatomic detail of all tissues & teeth are provided.
- The retromolar area, lingual frenum, tongue space, and mylohyoid
ridge are reproduced in a mand imp.
- The hard palate and tuberosities are recorded in a max imp.
◉ What's a term used to describe the change in temperature that
causes a reversible hydrocolloid material to transform from one
physical state to another? Answer: Hysteresis.
◉ Elastomeric impression materials are generally supplied in three
forms, what are they? Answer: Light-bodied (syringe-type or wash-
type), Regular-bodied, and heavy-bodied.
◉ What are the four types of elastomeric impression materials most
often used in dental practice? Answer: Polysulfide, polyether,
silicone, and polysiloxane(polyvinylsiloxane).
QUESTIONS AND DETAILED SOLUTIONS
◉ What type of mixing surface is ZOE mixed? Answer: An oil-
resistant paper pad that will not absorb any of the liquid, or when a
slower set is required use a glass slab.
◉ How is TempBond supplied? Answer: Two-paste system.
◉ Zinc Phosphate cements: Answer: Type I (fine-grain): used for
permanent cementation of cast restorations. Creates a very thing
film layer.
Type II (medium-grain): recommended for use as an insulating
based for deep cavity preparations.
◉ What should zinc phosphate be mixed on? Answer: A cool, dry,
thick glass slab because of the exothermic reaction that occurs when
zinc phosphate is mixed.
◉ What is the main component in the liquid form of zinc phosphate?
Answer: phosphoric acid, which is the component that is irritating to
the pulp.
,◉ What are the 3 classifications of impressions taken in dental
procedures? Answer: Preliminary, final, and occlusal (otherwise
known as a bite registration).
◉ Is an impression a negative or positive reproduction? Answer:
Negative. & the model poured is a positive reproduction.
◉ When selecting a stock tray for impressions, what must you look
for? Answer: - Patient comfort.
- Extends slightly beyond the facial surface of the teeth.
- Extends 2-3mm beyond the third molar, retromolar, or tuberosity
area of the arch.
- Sufficiently deep to allow 2-3mm of material between the tray and
incisal or occlusal edges of teeth.
◉ What type of wax is used when a tray needs to be extended or
more depth created? Answer: Utility wax.
◉ Which type of impression tray covers half of an arch? Answer:
Section trays.
◉ What are the main components of alginate? Answer: Potassium
alginate - derived from seaweed, used as a thickening agent.
Calcium sulfate - reacts with ^ to form the gel.
,Trisodium phosphate - slows down reaction for mixing.
Diatomaceous Earth - filler. adds bulk.
Zinc oxide - adds bulk.
Potassium titanium fluoride - prevents interference with the setting
and surface strength of the product.
◉ What is the name for the condition when alginate absorbs
additional water and expands? Answer: Imbibition.
◉ What is the name for the condition when moisture evaporates
from the material causing it to shrink? Answer: Syneresis.
◉ What types of setting does alginate come in? Answer: Normal set
& fast set.
◉ What does 'working time' refer to? Answer: The time allowed for
mixing the alginate, loading the tray, and positioning the tray in the
pt's mouth.
◉ What does 'setting time' refer to? Answer: The time required for
the chemical action to be complete, after which the impression is
ready or be removed from the patients mouth.
, ◉ What specific criteria must an acceptable alginate impression
meet? Answer: - Tray should be centered.
- A complete 'peripheral roll'
- Tray is not overseated.
- Impression is free from tears or voids.
- Sharp anatomic detail of all tissues & teeth are provided.
- The retromolar area, lingual frenum, tongue space, and mylohyoid
ridge are reproduced in a mand imp.
- The hard palate and tuberosities are recorded in a max imp.
◉ What's a term used to describe the change in temperature that
causes a reversible hydrocolloid material to transform from one
physical state to another? Answer: Hysteresis.
◉ Elastomeric impression materials are generally supplied in three
forms, what are they? Answer: Light-bodied (syringe-type or wash-
type), Regular-bodied, and heavy-bodied.
◉ What are the four types of elastomeric impression materials most
often used in dental practice? Answer: Polysulfide, polyether,
silicone, and polysiloxane(polyvinylsiloxane).
