Question 1

Which of the following types of gypsum products is also known as die stone?

Accepted Answer

A)  Dental stone 
B)  Model plaster 
C)  Impression plaster 
D)  High-strength/low-expansion dental stone 
E)  High-strength/high-expansion dental stone 
A)  Dental stone 
B)  Model plaster 
C)  Impression plaster 
D)  High-strength/low-expansion dental stone 
E)  High-strength/high-expansion dental stone D

Question 2

If a 2% solution of borax is added to the gypsum powder, what will happen to the setting time?

Accepted Answer

A)  Reduced slightly 
B)  Reduced significantly 
C)  Extended slightly 
D)  Extended significantly 
A)  Reduced slightly 
B)  Reduced significantly 
C)  Extended slightly 
D)  Extended significantly C

Question 3

Once the impression is removed from the mouth, list the steps for loading the impression tray.

Accepted Answer

1. Rinse the model with water to remove any debris or blood from the surface of the impression. Remove excess water from the impression.
2. Add a small amount of mixed gypsum material in one corner of the impression.
3. Place the impression gently on a vibrator to remove bubbles and then continue to add gypsum material.
4. Use a model former or use boxing wax to obtain the proper shape of the arch.
5. Add gypsum to the model former and invert the filled impression and place in the gypsum base. Do not trap the tray in set gypsum.
6. Allow gypsum material to set for 60 minutes until cool and dry before removing model.
7. Separate model from the impression.
8. Immediately clean the tray unless it is disposable.

Question 4

Which of the following statements is true of the production of dental stone?

Accepted Answer

A)  It is produced by heating gypsum in an open kettle. 
B)  The hemihydrate produced is b-calcium sulfate hemihydrate. 
C)  The hemihydrate produced is a-calcium sulfate hemihydrate. 
D)  A and B are true statements. 
E)  A and C are true statements. 
A)  It is produced by heating gypsum in an open kettle. 
B)  The hemihydrate produced is b-calcium sulfate hemihydrate. 
C)  The hemihydrate produced is a-calcium sulfate hemihydrate. 
D)  A and B are true statements. 
E)  A and C are true statements.

Question 5

Proper wetting occurs when gypsum is poured against a _____-based impression material such as ________.

Accepted Answer

A)  water; alginate 
B)  water; addition silicone 
C)  non-water; alginate 
D)  non-water; addition silicone 
A)  water; alginate 
B)  water; addition silicone 
C)  non-water; alginate 
D)  non-water; addition silicone

Question 6

When gypsum is mixed by hand, the mass is stirred with a spatula at a rate of about _____ revolution(s) per second for _________.

Accepted Answer

A)  five; about 5 minutes 
B)  two; about 2 minutes 
C)  two; about 1 minute 
D)  one; about 2 minutes 
E)  one; 30 seconds 
A)  five; about 5 minutes 
B)  two; about 2 minutes 
C)  two; about 1 minute 
D)  one; about 2 minutes 
E)  one; 30 seconds

Question 7

Dies can be constructed using digital data. Gypsum dies cannot be scanned for milling procedures.

Accepted Answer

A)  Statement 1 is correct; statement 2 is correct. 
B)  Statement 1 is correct; statement 2 is incorrect. 
C)  Statement 1 is incorrect; statement 2 is correct. 
D)  Statement 1 is incorrect; statement 2 is incorrect. 
A)  Statement 1 is correct; statement 2 is correct. 
B)  Statement 1 is correct; statement 2 is incorrect. 
C)  Statement 1 is incorrect; statement 2 is correct. 
D)  Statement 1 is incorrect; statement 2 is incorrect.

Question 8

Which of the following model and die materials are derived from the mineral gypsum?

Accepted Answer

A)  Dental stone 
B)  Model plaster 
C)  High-strength dental stone 
D)  A, B, and C 
E)  A and C 
A)  Dental stone 
B)  Model plaster 
C)  High-strength dental stone 
D)  A, B, and C 
E)  A and C

Question 9

What occurs if an excessive amount of water is used to prepare gypsum materials?

Accepted Answer

A)  A reduction in the setting time 
B)  Increased setting expansion 
C)  A reduction in strength 
D)  A, B, and C 
E)  A and C 
A)  A reduction in the setting time 
B)  Increased setting expansion 
C)  A reduction in strength 
D)  A, B, and C 
E)  A and C

Question 10

Water-powder ratio is defined as the amount of water in ___________ added to the amount of powder in _______.

Accepted Answer

A)  ounces; ounces 
B)  ounces; grams 
C)  milliliters; ounces 
D)  milliliters; grams 
A)  ounces; ounces 
B)  ounces; grams 
C)  milliliters; ounces 
D)  milliliters; grams

Question 11

________ are highly accurate replicas of a single tooth and generally are used to make metal crowns or inlays.

Accepted Answer

A)  Models 
B)  Casts 
C)  Dies 
D)  A and C 
E)  B and C 
A)  Models 
B)  Casts 
C)  Dies 
D)  A and C 
E)  B and C

Question 12

Dies of epoxy for use in fabrication of crowns, bridges, and inlays can be poured into alginate. Epoxy dies are tougher and more abrasion resistant than high-strength stone dies, and they are more accurate and stable dimensionally.

Accepted Answer

A)  Statement 1 is correct; statement 2 is correct. 
B)  Statement 1 is correct; statement 2 is incorrect. 
C)  Statement 1 is incorrect; statement 2 is correct. 
D)  Statement 1 is incorrect; statement 2 is incorrect. 
A)  Statement 1 is correct; statement 2 is correct. 
B)  Statement 1 is correct; statement 2 is incorrect. 
C)  Statement 1 is incorrect; statement 2 is correct. 
D)  Statement 1 is incorrect; statement 2 is incorrect.

Question 13

What are gypsum casts used for?

Accepted Answer

A)  Inlays 
B)  Crowns 
C)  Retainers 
D)  All of the above 
A)  Inlays 
B)  Crowns 
C)  Retainers 
D)  All of the above

Question 14

For high-strength die materials, reproduction of detail is not critical because a precision casting will be fabricated on the gypsum die. Reproduction of detail is measured by pouring the gypsum material against a metal die with lines of decreasing depth scribed on it.

Accepted Answer

A)  Statement 1 is correct; statement 2 is correct. 
B)  Statement 1 is correct; statement 2 is incorrect. 
C)  Statement 1 is incorrect; statement 2 is incorrect. 
D)  Statement 1 is incorrect; statement 2 is correct. 
A)  Statement 1 is correct; statement 2 is correct. 
B)  Statement 1 is correct; statement 2 is incorrect. 
C)  Statement 1 is incorrect; statement 2 is incorrect. 
D)  Statement 1 is incorrect; statement 2 is correct.

Question 15

What happens if alginate dries out before the gypsum is poured?

Accepted Answer

A)  The alginate will rob the gypsum mix of some of its water. 
B)  The edges of the alginate may tear off. 
C)  The impression will be distorted. 
D)  A, B, and C are correct. 
E)  A and C are correct. 
A)  The alginate will rob the gypsum mix of some of its water. 
B)  The edges of the alginate may tear off. 
C)  The impression will be distorted. 
D)  A, B, and C are correct. 
E)  A and C are correct.

Question 16

Why do high-strength stone crystals require the least amount of excess water?

Accepted Answer

A)  Large and dense 
B)  Large and sparse 
C)  Small and dense 
D)  Small and sparse 
A)  Large and dense 
B)  Large and sparse 
C)  Small and dense 
D)  Small and sparse

Question 17

What is a good way to determine the final setting time of gypsum material?

Accepted Answer

A)  Loss of surface gloss 
B)  Dissipation of the heat of reaction 
C)  When the material can no longer be poured 
D)  When the conversion of hemihydrate to dihydrate is complete 
A)  Loss of surface gloss 
B)  Dissipation of the heat of reaction 
C)  When the material can no longer be poured 
D)  When the conversion of hemihydrate to dihydrate is complete

Question 18

Orthodontic plaster is a mixture of what two compounds?

Accepted Answer

A)  Model plaster and dental stone 
B)  Impression plaster and dental stone 
C)  Impression plaster and model plaster 
D)  High-strength/low-expansion and high-strength/high-expansion dental stone 
A)  Model plaster and dental stone 
B)  Impression plaster and dental stone 
C)  Impression plaster and model plaster 
D)  High-strength/low-expansion and high-strength/high-expansion dental stone

Question 19

If gypsum materials are not adequately spatulated, _______________ suffers.

Accepted Answer

A)  strength 
B)  accuracy 
C)  abrasion resistance 
D)  dimensional change 
A)  strength 
B)  accuracy 
C)  abrasion resistance 
D)  dimensional change

Question 20

How is the final setting time of gypsum defined?

Accepted Answer

A)  The point where the gypsum can be removed without distortion 
B)  The point where the gypsum can be removed without fracture 
C)  The point where the exothermic reaction is complete 
D)  All of the above 
E)  Only A and B 
A)  The point where the gypsum can be removed without distortion 
B)  The point where the gypsum can be removed without fracture 
C)  The point where the exothermic reaction is complete 
D)  All of the above 
E)  Only A and B

Which of the following types of gypsum products is also known as die stone?

If a 2% solution of borax is added to the gypsum powder, what will happen to the setting time?

Once the impression is removed from the mouth, list the steps for loading the impression tray.

Which of the following statements is true of the production of dental stone?

Proper wetting occurs when gypsum is poured against a _-based impression material such as ____.

When gypsum is mixed by hand, the mass is stirred with a spatula at a rate of about _ revolution(s) per second for _____.

Dies can be constructed using digital data. Gypsum dies cannot be scanned for milling procedures.

Which of the following model and die materials are derived from the mineral gypsum?

What occurs if an excessive amount of water is used to prepare gypsum materials?

Water-powder ratio is defined as the amount of water in _____ added to the amount of powder in _.

________ are highly accurate replicas of a single tooth and generally are used to make metal crowns or inlays.

Dies of epoxy for use in fabrication of crowns, bridges, and inlays can be poured into alginate. Epoxy dies are tougher and more abrasion resistant than high-strength stone dies, and they are more accurate and stable dimensionally.

What are gypsum casts used for?

For high-strength die materials, reproduction of detail is not critical because a precision casting will be fabricated on the gypsum die. Reproduction of detail is measured by pouring the gypsum material against a metal die with lines of decreasing depth scribed on it.

What happens if alginate dries out before the gypsum is poured?

Why do high-strength stone crystals require the least amount of excess water?

What is a good way to determine the final setting time of gypsum material?

Orthodontic plaster is a mixture of what two compounds?

If gypsum materials are not adequately spatulated, _______________ suffers.

How is the final setting time of gypsum defined?

Introduction to Restorative Dental Materials

Properties of Materials

Preventive Dental Materials

Direct Esthetic Restorative Materials

Dental Amalgam

Finishing, Polishing, and Cleansing Materials

Cements

Impression Materials

Waxes

Casting Alloys, Wrought Alloys, and Solders

Casting, Soldering, and Welding

Polymers in Prosthodontics

Dental Ceramics

Dental Implants

Filters

Exam 9: Model and Die Materials

Which of the following types of gypsum products is also known as die stone?

If a 2% solution of borax is added to the gypsum powder, what will happen to the setting time?

Once the impression is removed from the mouth, list the steps for loading the impression tray.

Which of the following statements is true of the production of dental stone?

Proper wetting occurs when gypsum is poured against a _____-based impression material such as ________.

When gypsum is mixed by hand, the mass is stirred with a spatula at a rate of about _____ revolution(s) per second for _________.

Dies can be constructed using digital data. Gypsum dies cannot be scanned for milling procedures.

Which of the following model and die materials are derived from the mineral gypsum?

What occurs if an excessive amount of water is used to prepare gypsum materials?

Water-powder ratio is defined as the amount of water in ___________ added to the amount of powder in _______.

________ are highly accurate replicas of a single tooth and generally are used to make metal crowns or inlays.

Dies of epoxy for use in fabrication of crowns, bridges, and inlays can be poured into alginate. Epoxy dies are tougher and more abrasion resistant than high-strength stone dies, and they are more accurate and stable dimensionally.

What are gypsum casts used for?

For high-strength die materials, reproduction of detail is not critical because a precision casting will be fabricated on the gypsum die. Reproduction of detail is measured by pouring the gypsum material against a metal die with lines of decreasing depth scribed on it.

What happens if alginate dries out before the gypsum is poured?

Why do high-strength stone crystals require the least amount of excess water?

What is a good way to determine the final setting time of gypsum material?

Orthodontic plaster is a mixture of what two compounds?

If gypsum materials are not adequately spatulated, _______________ suffers.

How is the final setting time of gypsum defined?

Introduction to Restorative Dental Materials

Properties of Materials

Preventive Dental Materials

Direct Esthetic Restorative Materials

Dental Amalgam

Finishing, Polishing, and Cleansing Materials

Cements

Impression Materials

Waxes

Casting Alloys, Wrought Alloys, and Solders

Casting, Soldering, and Welding

Polymers in Prosthodontics

Dental Ceramics

Dental Implants

Filters

Proper wetting occurs when gypsum is poured against a _-based impression material such as ____.

When gypsum is mixed by hand, the mass is stirred with a spatula at a rate of about _ revolution(s) per second for _____.

Water-powder ratio is defined as the amount of water in _____ added to the amount of powder in _.