Question 1

A plaster mix should not be:

Accepted Answer

A) completed in 2 minutes. 
B) pressed lightly on the vibrator. 
C) completed in 30 seconds. 
D) mixed slowly. 
A) completed in 2 minutes. 
B) pressed lightly on the vibrator. 
C) completed in 30 seconds. 
D) mixed slowly. C

Question 2

The first step in making a custom tray is to:

Accepted Answer

A) prepare the resin. 
B) make a spacer. 
C) prepare a diagnostic model. 
D) place blockout material. 
A) prepare the resin. 
B) make a spacer. 
C) prepare a diagnostic model. 
D) place blockout material. C

Question 3

Type _____ baseplate wax is a softer wax used for denture construction.

Accepted Answer

A) I 
B) II 
C) III 
A) I 
B) II 
C) III A

Question 4

________ wax is pre-formed with a thin sheet of aluminum foil between the layers.

Accepted Answer

A) Sticky 
B) Inlay casting 
C) Baseplate 
D) Bite registration 
A) Sticky 
B) Inlay casting 
C) Baseplate 
D) Bite registration

Question 5

A custom impression tray should fit and adapt well to the model and should maintain ____ mm of impression material between itself and the teeth.

Accepted Answer

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

Question 6

When pouring an impression,the plaster should not be placed:

Accepted Answer

A) in small increments. 
B) in large amounts. 
C) to the same place. 
D) in a continuous flow. 
A) in small increments. 
B) in large amounts. 
C) to the same place. 
D) in a continuous flow.

Question 7

The type of resin that is formed into a diagnostic model using heat and a vacuum is:

Accepted Answer

A) self-cured. 
B) light-cured. 
C) thermoplastic. 
D) auto-cured. 
A) self-cured. 
B) light-cured. 
C) thermoplastic. 
D) auto-cured.

Question 8

A dental assistant should wait _____ minutes before removing a model from an impression.

Accepted Answer

A) 10 
B) 15 
C) 30 
D) 45 to 60 
A) 10 
B) 15 
C) 30 
D) 45 to 60

Question 9

Which of the following gypsum products has the highest powder-to-water ratio?

Accepted Answer

A) Model plaster 
B) Dental stone 
C) High-strength stone 
D) All gypsum products have the same powder-to-water ratio. 
A) Model plaster 
B) Dental stone 
C) High-strength stone 
D) All gypsum products have the same powder-to-water ratio.

Question 10

When positioning the bite-fork in the patient's mouth during a face-bow registration,the patient should bite:

Accepted Answer

A) quickly. 
B) firmly. 
C) slowly. 
D) and slide. 
A) quickly. 
B) firmly. 
C) slowly. 
D) and slide.

Question 11

Infection control in the dental laboratory is:

Accepted Answer

A) as important as it is when you are with a patient. 
B) not as critical as it is when you are with a patient. 
C) not a consideration because impressions are disinfected before entering the dental laboratory. 
D) all of the above. 
A) as important as it is when you are with a patient. 
B) not as critical as it is when you are with a patient. 
C) not a consideration because impressions are disinfected before entering the dental laboratory. 
D) all of the above.

Question 12

Water should be running through a model trimmer:

Accepted Answer

A) never. 
B) at all times when trimming. 
C) after trimming. 
D) before trimming only. 
A) never. 
B) at all times when trimming. 
C) after trimming. 
D) before trimming only.

Question 13

Air bubbles in a stone cast are caused by:

Accepted Answer

A) using a vibrator. 
B) adding stone in small increments. 
C) impression material that is too thick. 
D) improper pouring of the impression. 
A) using a vibrator. 
B) adding stone in small increments. 
C) impression material that is too thick. 
D) improper pouring of the impression.

Question 14

Light-cured resin tray material should be cured:

Accepted Answer

A) for 10 minutes. 
B) off the model. 
C) for 2 minutes. 
D) without the spacer. 
A) for 10 minutes. 
B) off the model. 
C) for 2 minutes. 
D) without the spacer.

Question 15

Safety precautions in the laboratory include all except:

Accepted Answer

A) PPE should be worn while working in the laboratory. 
B) manufacturer's instructions should be followed for equipment operation. 
C) this is the appropriate place for eating and drinking in the dental office. 
D) the work areas should be kept clean before and after procedures. 
A) PPE should be worn while working in the laboratory. 
B) manufacturer's instructions should be followed for equipment operation. 
C) this is the appropriate place for eating and drinking in the dental office. 
D) the work areas should be kept clean before and after procedures.

Question 16

When mixing gypsum,it is important to use the correct amount of water and powder.If additional powder is added after mixing has begun,the mix will be:

Accepted Answer

A) stronger. 
B) weaker. 
C) unaffected. 
D) none of the above. 
A) stronger. 
B) weaker. 
C) unaffected. 
D) none of the above.

Question 17

A light gauge of vacuum-formed resin material is used for:

Accepted Answer

A) bleaching trays. 
B) provisional coverage. 
C) impression tray. 
D) both a and b. 
A) bleaching trays. 
B) provisional coverage. 
C) impression tray. 
D) both a and b.

Question 18

The _________ is the measurement of where the teeth are positioned when the joints are aligned correctly and before the teeth actually come together.

Accepted Answer

A) bite record 
B) articulator 
C) centric relation 
D) both a and c 
A) bite record 
B) articulator 
C) centric relation 
D) both a and c

Question 19

The powder-to-water ratio for high-strength stone is ___:100.

Accepted Answer

A) 45 
B) 30 
C) 19 
D) 12 
A) 45 
B) 30 
C) 19 
D) 12

Question 20

The _____ is used to polish or trim custom trays,provisional coverage,dentures,and indirect restorations.

Accepted Answer

A) sandblaster 
B) model trimmer 
C) vacuum former 
D) dental lathe 
A) sandblaster 
B) model trimmer 
C) vacuum former 
D) dental lathe

Exam 47: Laboratory Materials and Procedures

A plaster mix should not be:

The first step in making a custom tray is to:

Type _____ baseplate wax is a softer wax used for denture construction.

________ wax is pre-formed with a thin sheet of aluminum foil between the layers.

A custom impression tray should fit and adapt well to the model and should maintain ____ mm of impression material between itself and the teeth.

When pouring an impression,the plaster should not be placed:

The type of resin that is formed into a diagnostic model using heat and a vacuum is:

A dental assistant should wait _____ minutes before removing a model from an impression.

Which of the following gypsum products has the highest powder-to-water ratio?

When positioning the bite-fork in the patient's mouth during a face-bow registration,the patient should bite:

Infection control in the dental laboratory is:

Water should be running through a model trimmer:

Air bubbles in a stone cast are caused by:

Light-cured resin tray material should be cured:

Safety precautions in the laboratory include all except:

When mixing gypsum,it is important to use the correct amount of water and powder.If additional powder is added after mixing has begun,the mix will be:

A light gauge of vacuum-formed resin material is used for:

The _________ is the measurement of where the teeth are positioned when the joints are aligned correctly and before the teeth actually come together.

The powder-to-water ratio for high-strength stone is ___:100.

The _____ is used to polish or trim custom trays,provisional coverage,dentures,and indirect restorations.

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

Impression Materials

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