Question 1

What are the three classifications of impressions used in dentistry?

Accepted Answer

A) Prospective, retrospective, and introspective 
B) Preliminary, functional, and occlusal, or bite, registration 
C) Preliminary, final, and occlusal, or bite, registration 
D) Diagnostic, functional, and determinative 
A) Prospective, retrospective, and introspective 
B) Preliminary, functional, and occlusal, or bite, registration 
C) Preliminary, final, and occlusal, or bite, registration 
D) Diagnostic, functional, and determinative

Question 2

Why must impression trays be rigid?

Accepted Answer

A) Support the material in the patient's mouth. 
B) Warp the completed impression. 
C) Both a and b are correct. 
D) Neither are correct. 
A) Support the material in the patient's mouth. 
B) Warp the completed impression. 
C) Both a and b are correct. 
D) Neither are correct.

Question 3

Which irreversible hydrocolloid material is used most widely for preliminary impressions?

Accepted Answer

A) Light-bodied 
B) Alginate 
C) Polysulfide 
D) Polyether 
A) Light-bodied 
B) Alginate 
C) Polysulfide 
D) Polyether

Question 4

How can length or depth of the alginate impression tray borders be extended?

Accepted Answer

A) Utility wax 
B) Acrylic 
C) Boxing wax 
D) Border molding compound 
A) Utility wax 
B) Acrylic 
C) Boxing wax 
D) Border molding compound

Question 5

An impression is a positive reproduction of teeth and surrounding oral tissues.The model created from the impression is a negative reproduction of the structures.

Accepted Answer

A) Both statements are correct. 
B) Neither statement is correct. 
C) The first statement is correct; the second statement is incorrect. 
D) The first statement is incorrect; the second statement is correct. 
A) Both statements are correct. 
B) Neither statement is correct. 
C) The first statement is correct; the second statement is incorrect. 
D) The first statement is incorrect; the second statement is correct.

Question 6

Which type of elastomeric material has the highest viscosity?

Accepted Answer

A) Light-bodied 
B) Regular-bodied 
C) Heavy-bodied 
D) Putty 
A) Light-bodied 
B) Regular-bodied 
C) Heavy-bodied 
D) Putty

Question 7

Although technique may vary,when assisting a dentist in taking an elastomeric impression,mix the light-bodied material first.

Accepted Answer

A) True 
 B)False

Question 8

Which impression material is used when an extremely accurate final impression is essential?

Accepted Answer

A) Elastomeric 
B) Alginate 
C) Reversible hydrocolloid 
D) Light-cured 
A) Elastomeric 
B) Alginate 
C) Reversible hydrocolloid 
D) Light-cured

Question 9

Elastomeric materials use an Automix system.The extruder gun insert is either catalyst or base.

Accepted Answer

A) Both statements are correct. 
B) Neither statement is correct. 
C) The first statement is correct; the second statement is incorrect. 
D) The first statement is incorrect; the second statement is correct. 
A) Both statements are correct. 
B) Neither statement is correct. 
C) The first statement is correct; the second statement is incorrect. 
D) The first statement is incorrect; the second statement is correct.

Question 10

How will a water temperature of 80° F (26.6° C)affect an alginate mix?

Accepted Answer

A) It will make the mix set faster. 
B) It will not change the setting time. 
C) It will make the mix set slower. 
D) It will render the mix useless. 
A) It will make the mix set faster. 
B) It will not change the setting time. 
C) It will make the mix set slower. 
D) It will render the mix useless.

Question 11

What percent relative humidity is preferred for storing impressions?

Accepted Answer

A) 10 
B) 35 
C) 70 
D) 100 
A) 10 
B) 35 
C) 70 
D) 100

Question 12

What are the three curing stages of impression materials?

Accepted Answer

A) First impression, setting phase, final impression 
B) Initial set, final set, final cure 
C) Initial impression, curing stage, final impression 
D) First set, curing set, final set 
A) First impression, setting phase, final impression 
B) Initial set, final set, final cure 
C) Initial impression, curing stage, final impression 
D) First set, curing set, final set

Question 13

Which factor should be examined when evaluating the quality of an impression?

Accepted Answer

A) The presence of the retromolar area and maxillary tuberosity are recorded. 
B) Anatomical detail is sharp and not distorted. 
C) Surfaces are free from voids. 
D) All of the above are factors. 
A) The presence of the retromolar area and maxillary tuberosity are recorded. 
B) Anatomical detail is sharp and not distorted. 
C) Surfaces are free from voids. 
D) All of the above are factors.

Question 14

What does the term syneresis mean as it relates to alginate impression?

Accepted Answer

A) Water evaporates from the impression. 
B) The mix changes colors. 
C) Excess moisture is absorbed by the impression. 
D) The mixing time is increased. 
A) Water evaporates from the impression. 
B) The mix changes colors. 
C) Excess moisture is absorbed by the impression. 
D) The mixing time is increased.

Question 15

Which type of reversible hydrocolloid material is the most viscous?

Accepted Answer

A) Syringe 
B) Plate 
C) Tempered 
D) Tray 
A) Syringe 
B) Plate 
C) Tempered 
D) Tray

Question 16

Which of the following is not true regarding an automix system?

Accepted Answer

A) Elastomeric impression materials are automatically mixed and dispensed via an extruder. 
B) The unit can be used with light-bodied material only. 
C) It provides appropriate amount of material without waste. 
D) Both b and C 
A) Elastomeric impression materials are automatically mixed and dispensed via an extruder. 
B) The unit can be used with light-bodied material only. 
C) It provides appropriate amount of material without waste. 
D) Both b and C

Question 17

An impression tray should be sufficiently deep to allow _____ mm of material between the tray and the incisal or occlusal edges of the teeth.

Accepted Answer

A) 0.5 to 1 
B) 2 to 3 
C) 4 to 5 
D) 6 to 7 
A) 0.5 to 1 
B) 2 to 3 
C) 4 to 5 
D) 6 to 7

Question 18

Which material should be used if a more durable impression material is needed for bite registration?

Accepted Answer

A) Polysulfide 
B) Zinc oxide-eugenol 
C) Polysiloxane 
D) Reversible hydrocolloid 
A) Polysulfide 
B) Zinc oxide-eugenol 
C) Polysiloxane 
D) Reversible hydrocolloid

Question 19

Which statement is correct regarding custom impression trays?

Accepted Answer

A) They are made from a preliminary model after the dentist has prepared the teeth. 
B) They can be constructed from resin. 
C) They are available only as full-arch trays. 
D) They do not require adhesive if they are smooth surface. 
A) They are made from a preliminary model after the dentist has prepared the teeth. 
B) They can be constructed from resin. 
C) They are available only as full-arch trays. 
D) They do not require adhesive if they are smooth surface.

Question 20

What can be done to alleviate the gag reflex when taking alginate impressions?

Accepted Answer

A) Use fast-set alginate, because it allows the impression tray to be removed from the mouth much sooner than if using normal set alginate. 
B) Do not overload the posterior regions of the trays. 
C) Have the patient take deep breaths through the nose. 
D) All of the above can be done. 
A) Use fast-set alginate, because it allows the impression tray to be removed from the mouth much sooner than if using normal set alginate. 
B) Do not overload the posterior regions of the trays. 
C) Have the patient take deep breaths through the nose. 
D) All of the above can be done.

Exam 46: Impression Materials

What are the three classifications of impressions used in dentistry?

Why must impression trays be rigid?

Which irreversible hydrocolloid material is used most widely for preliminary impressions?

How can length or depth of the alginate impression tray borders be extended?

An impression is a positive reproduction of teeth and surrounding oral tissues.The model created from the impression is a negative reproduction of the structures.

Which type of elastomeric material has the highest viscosity?

Although technique may vary,when assisting a dentist in taking an elastomeric impression,mix the light-bodied material first.

Which impression material is used when an extremely accurate final impression is essential?

Elastomeric materials use an Automix system.The extruder gun insert is either catalyst or base.

How will a water temperature of 80° F (26.6° C)affect an alginate mix?

What percent relative humidity is preferred for storing impressions?

What are the three curing stages of impression materials?

Which factor should be examined when evaluating the quality of an impression?

What does the term syneresis mean as it relates to alginate impression?

Which type of reversible hydrocolloid material is the most viscous?

Which of the following is not true regarding an automix system?

An impression tray should be sufficiently deep to allow _____ mm of material between the tray and the incisal or occlusal edges of the teeth.

Which material should be used if a more durable impression material is needed for bite registration?

Which statement is correct regarding custom impression trays?

What can be done to alleviate the gag reflex when taking alginate impressions?

History of Dentistry

The Professional Dental Assistant

The Dental Healthcare Team

Dental Ethics

Dentistry and the Law

General Anatomy

General Physiology

Oral Embryology and Histology

Head and Neck Anatomy

Landmarks of the Face and Oral Cavity

Overview of the Dentitions

Tooth Morphology

Dental Caries

Periodontal Disease

Preventive Dentistry

Nutrition

Oral Pathology

Microbiology

Disease Transmission and Infection Prevention

Principles and Techniques of Disinfection

Principles and Techniques of Instrument Processing and Sterilization

Regulatory and Advisory Agencies

Chemical and Waste Management

Dental Unit Waterlines

Ergonomics

The Patient Record

Vital Signs

Oral Diagnosis and Treatment Planning

The Special Needs and Medically Compromised Patient

Principles of Pharmacology

Assisting in a Medical Emergency

The Dental Office

Delivering Dental Care

Dental Hand Instruments

Dental Handpieces and Accessories

Moisture Control

Anesthesia and Pain Control

Foundations of Radiography, Radiographic Equipment, and Radiation Safety

Digital Imaging, Dental Film, and Processing Radiographs

Legal Issues, Quality Assurance, and Infection Prevention

Intraoral Imaging

Extraoral Imaging

Restorative and Esthetic Dental Materials

Dental Liners, Bases, and Bonding Systems

Dental Cements

Laboratory Materials and Procedures

General Dentistry

Matrix Systems for Restorative Dentistry

Fixed Prosthodontics

Provisional Coverage

Removable Prosthodontics

Dental Implants

Endodontics

Periodontics

Oral and Maxillofacial Surgery

Pediatric Dentistry

Coronal Polishing

Dental Sealants

Orthodontics