Midterm Dental Materials Wk1-5 Combined

A dental material that is classified by longevity of use includes all of the following EXCEPT:

Temporary restoration

Permanent restoration

Partial restoration

Interim restoration

Partial restoration

An example of a Class II medical device is:

Composite restorative material

A toothbrush

Bone graft material

Prophy paste

Composite restorative material

Class __________ lesions involve the cusp tip or incisal edge of a tooth (and were not part of Black's original classifications).

I

III

VI

V

VI

Class __________ restorations are often placed as a result of trauma and involve the incisal angle of an anterior tooth.

IV

III

VI

II

IV

Dental caries involving the area just below the interproximal contact is referred to as:

Class III

Class I

Class V

Class II

Class II

Dental materials that are tooth colored are called __________ materials?

Hygienic

Esthetic

Prosthetic

Cosmetic

Esthetic

The ADA Seal of Acceptance is issued to a product that follows ADA guidelines for a period of how many years?

5 years

3 years

6 years

Lifetime

3 years

The Council on Scientific Affairs, which develops standards for dental products, operates under the guidance of which organization?

ANSI

ADA

DMD

ADSI

ANSI

The most reliable source of information about a dental product comes from:

Manufacturer's data

Clinical trials

Package inserts

Hands-on experience

Clinical trials

Which of the following is NOT an example of a dental material?

Amalgam filling

Porcelain crown

Full maxillary denture

Fluoride varnish

Fluoride varnish

All of the following are reasons for a dental hygienist to have knowledge and understanding of dental materials EXCEPT:

Explaining the different types of restorative materials available to the patient

Assessing the patient's oral condition

Deciding which material is best for the patient's restoration

Understanding the behavior of dental materials

Deciding which material is best for the patient's restoration

An amalgam restoration located on the gingival third of tooth #3 would be a Class _____ restoration.

I

II

III

IV

V

VI

V

An example of an indirect restorative material would be:

Amalgam

Glass ionomer cement

Composite

Ceramic (porcelain)

Ceramic (porcelain)

If a restoration is fabricated on a replica (positive reproduction) of a patient's teeth, it is referred to as a:

Student model

Cast

Diagnostic cast

Any of the above terms may be used

Cast

In the United States, standards for dental materials are developed and administered by the:

FDA (Food and Drug Administration)

ADA (American Dental Association)

AADR (American Association for Dental Research)

OSHA (Occupational Safety and Health Administration)

ADA (American Dental Association)

Medical devices are grouped into three categories according to Medical Device Amendment of 1976. Which class of devices is most regulated?

I

II

III

IV

III

The biologic nature of the oral environment and the size of the oral cavity restrict the use of dental materials. One restriction is the degradation of restorations.

The first statement is true; the second statement is false.

The first statement is false; the second statement is true.

Both statements are true.

Both statements are false.

Both statements are true.

The design of a cavity preparation aids in the retention of a restoration. The walls of an amalgam preparation diverge while the walls of an inlay converge.

The first statement is true; the second statement is false.

The first statement is false; the second statement is true.

Both statements are true.

Both statements are false.

The first statement is true; the second statement is false.

Using Figure 1.9A and D, which of the following best describes the roots of the teeth?

Calculus is visible on the distal of tooth #2.

Calculus is visible on several roots.

The roots are radiographically foreshortened.

The roots are radiographically elongated.

Calculus is visible on the distal of tooth #2.

When the temperature changes in the mouth, the teeth and most restorative materials expand and contract by the same amount. No leakage occurs around the restoration.

The first statement is true; the second statement is false.

The first statement is false; the second statement is true.

Both statements are true.

Both statements are false.

Both statements are false.

Which of the following oral tissues provides feedback to the individual regarding the forces placed on the tooth?

Pulp

Dentin

Periodontium

Gingival tissue

Periodontium

Which of the following restorations is utilized when a substantial amount of a tooth is missing?

Crown

Pontic

Implant

Fixed partial denture

Crown

Cathy and her parents will meet with an orthodontist to discuss an orthodontic treatment plan. At a previous appointment, the orthodontist took impressions of Cathy's maxillary and mandibular arches. The replicas made from each impression to discuss the treatment plan are termed:

Casts

Dies

Study models

Molds

Study models

Decreasing the setting time of a dental material results in a product that:

Will set faster

Will set slower

Does not affect the setting time

Enhances the properties

Will set faster

For gypsum products, a suitable accelerator and retarder, respectively, would be:

Ethyl alcohol and oleic acid

Oleic acid and glycerin

Borax and potassium sulfate

Potassium sulfate and borax

Potassium sulfate and borax

Initial and final setting times of gypsum can be determined with the use of Gillmore needles. A practical, easy method to determine final setting time in a dental office would be to:

Set a timer for 20 minutes

Observe the change from wet to dry strength

Watch for the loss of gloss

Attempt to penetrate the material with the metal spatula

Attempt to penetrate the material with the metal spatula

The best way to mix gypsum products is to:

"Eyeball" the amount of powder added to water

Add water to the powder

Add powder to the water

Add powder and water to bowl simultaneously

Add powder to the water

The desirable strength of gypsum materials is_____related to the amount of water used.

Directly

Indirectly

Not

Partially

Directly

The final setting time in minutes for gypsum products typically is:

15 to 30

30 to 45

45 to 90

90 to 120

30 to 45

The gypsum material known as "high-strength stone" may also be referred to as:

Plaster

Dental stone

Type III stone

Improved stone

Improved stone

The weakest gypsum product is:

Improved stone

Dental stone

Plaster

Die stone

Plaster

To make a correct mix for dental stone when using 50 g of powder, the amount of water would be approximately:

10 to 12 mL

14 to 15 mL

28 to 30 mL

45 to 50 mL

14 to 15 mL

When excess water is not present in a gypsum product, it is known as the:

Wet strength

Dry strength

Initial setting time

Surface strength

Dry strength

When the setting time of a dental material is increased, which of the following is true?

The material sets slower

The material sets faster

The setting reaction does not change

The setting reaction is increased

The material sets slower

For what purpose is a study model NOT used?

To fabricate a restoration, or appliance

To plan treatment

To educate the patient about his or her own oral health

To track the progress of a current treatment

To fabricate a restoration, or appliance

On which type of model is a restoration or appliance fabricated?

Full arch model

Study model

Die

Cast

cast

Plaster is also known as Type __________, and Stone is known as Type __________ gypsum.

II, III

I, II

III, II

II, I

II, III

The length of time from the start of the mix until the setting mass becomes rigid is called:

Working time

Initial setting time

Mixing time

Final setting time

Final setting time

The length of time from the start of the mix until the setting mass reaches a semi-hard stage is called:

Final setting time

Curing time

Initial setting time

Mixing time

Initial setting time

The material used to attach casts to an articulator, or when strength is not critical is:

Stone

Plaster

Improved stone

Gypsum

When hand mixing, it is important to use a __________ motion and avoid a __________ one.

Stirring, stropping

Wiping, whipping

Stropping, stirring

Whipping, wiping

Wiping, whipping

When mixing, adding powder to the water results in:

Assured proper consistency

Low strength

Irregular consistency

Inconsistent expansion

Assured proper consistency

Which of the following will decrease the setting time of a gypsum product?

Decreased mixing

Addition of a chemical accelerator (i.e., potassium)

Higher water/powder ratio (thinner mix)

Addition of a chemical retarder (i.e., borax)

Addition of a chemical accelerator (i.e., potassium)

__________ indicates the major completion of the hydration reaction.

Working time

Initial set time

Final set time

Curing time

Final set time

A beneficial chemical process in manufacturing that creates a thin layer of chromium oxide on the surface of the instrument to protect it from corrosion is called:

Manufacture of alloy

Electroplating

Passivation

Electropolishing

Passivation

A uniform corrosive attack that produces a film or surface layer on the metal is termed:

Corrosion

Tarnish

Electrochemical corrosion

Concentration cell corrosion

Tarnish

Risks are involved when re-tipping instruments. One of these risks is frequent breakage between the shank and tip.

The first statement is true; the second statement is false.

The first statement is false; the second statement is true.

Both statements are true.

Both statements are false.

The first statement is true; the second statement is false.

The dry heat method of sterilization is used when:

Ventilation is not adequate

Items cannot withstand temperatures greater than 270°F

Items cannot withstand compressed steam conditions

Items are needed for the next patient

Items cannot withstand compressed steam conditions

The major components of stainless steel alloy are:

Tin, chromium, and nickel

Iron, silver, and nickel

Iron, aluminum, and nickel

Iron, chromium, and nickel

Iron, chromium, and nickel

The major disadvantage of using noble metals for the fabrication of instruments is:

Cost

Corrosion

Wear rate

Pitting

cost

The name of the procedure that produces a smooth, highly polished finish on an instrument is:

Passivation

Electropolishing

Heat treatment polishing

Cryogenic polishing

Electropolishing

The standard protocol for chemical vapor sterilization is:

270°F at 27 psi for at least 6 minutes

320°F for approximately 2 hours

270°F at 20 to 40 psi for at least 10 minutes

270°F at 20 to 40 psi for at least 20 minutes

270°F at 20 to 40 psi for at least 20 minutes

To determine when the instruments should be sharpened, this chapter provides_____questions to ask when looking over the appointment book so that an effective sharpening schedule may be developed.

2

3

4

5

3

Which of the following sequence of steps is correct for the instrument maintenance cycle?

Use and maintain, sharpen, sterilize, inspect, wash/ultrasonic clean

Sharpen, inspect, use and maintain, sterilize, wash/ultrasonic clean

Use and maintain, inspect, wash/ultrasonic clean, sterilize, sharpen

Use and maintain, inspect, wash/ultrasonic clean, sharpen, sterilize

Use and maintain, inspect, wash/ultrasonic clean, sterilize, sharpen

Carbon steel alloy instruments differ from stainless steel instruments in that:

They are less susceptible to corrosion

They do not stay sharp as long

They are softer

They are more sensitive to chemicals

They are more sensitive to chemicals

Corrosion occurs because the metal-oxide that results is the __________-energy form of the meal.

Lower

Higher

Neutral

Stable

lower

Identify the item listed that is NOT a reason for instrument sharpening.

Reduced clinician fatigue

Improved tactile sensitivity

Less burnished calculus

Increased patient discomfort

Increased patient discomfort

Passivation creates a thin but tough layer of __________ on the surface of the instrument.

Chromium oxide

Aluminum oxide

Chromium peroxide

Stainless steel

Chromium oxide

Tarnish is a(n) __________ attack on the surface of a metal.

Chemical

Electrochemical

Environmental

Electrical

Electrochemical

What component of stainless steel instruments is directly related to the instrument's hardness?

Chromium

Carbon

Nickel

Steel

carbon

Which statement is NOT true about cleaning instruments after patient care?

Presoak solutions are to be whenever timely cleaning is not possible.

Enzymatic cleaners digest blood proteins and other debris.

Ultrasonic cleaning is necessary for visibly soiled instruments only.

Hand scrubbing is not advised due to increased risk of splatter.

Ultrasonic cleaning is necessary for visibly soiled instruments only.

Which type of sterilization is most effective for destroying pathogenic organisms or their vegetative forms?

Which type of sterilization is most effective for destroying pathogenic organisms or their vegetative forms?

Steam autoclave

Unsaturated chemical vapor

Dry heat

Chemical solution

Steam autoclave

Why does electropolishing make an instrument less likely to corrode?

The chemical interactions.

The highly polished finish.

It forms an alloy with the material.

It creates a layer of chromium oxide.

The highly polished finish.

__________ occurs when two dissimilar metals in a wet environment cause a current to flow.

Tarnish

Corrosion

Galvanic corrosion

Spotting

Galvanic corrosion

According to CDC guidelines, how often should biological monitoring of sterilizers be conducted?

At least weekly

At least monthly

For every sterilizer load

Only if the sterilizer is malfunctioning

At least weekly

According to Spaulding's Classification of Inanimate Objects, critical items are those items that may penetrate soft tissue or bone. These items must be sterilized by heat or high-level disinfection.

The first statement is true; the second statement is false.

The first statement is false; the second statement is true.

Both statements are true.

Both statements are false.

The first statement is true; the second statement is false.

All of the following chemicals are acceptable surface disinfectants except one. Which one is the EXCEPTION?

Phenols

Iodophors

Chlorine

Quaternaries

Glutaraldehydes

Glutaraldehydes

An acceptable surface disinfectant must be tuberculocidal and kill both hydrophilic and lipophilic viruses. Hydrophilic viruses are much harder to kill than lipophilic viruses.

The first statement is true; the second statement is false.

The first statement is false; the second statement is true.

Both statements are true.

Both statements are false.

Both statements are true.

Anesthetic needles, orthodontic wire, irrigation needles, and anesthetic cartridges must not be discarded in the regular trash. These items must be discarded in appropriately labeled cardboard boxes or plastic bags.

The first statement is true; the second statement is false.

The first statement is false; the second statement is true.

Both statements are true.

Both statements are false.

The first statement is true; the second statement is false.

By OSHA mandate, the dental care provider must wear appropriate PPE (glove, mask, eye protection, and clothing) during patient care involving contact with blood and saliva. This PPE should be worn only in the clinical treatment area.

The first statement is true; the second statement is false.

The first statement is false; the second statement is true.

Both statements are true.

Both statements are false.

Both statements are true.

Hands should be washed before putting on and after removing gloves. If not visibly soiled and for nonsurgical procedures, hands may be cleaned by applying an alcohol-based solution and rubbing the hands for 15 seconds until the agent is dry.

The first statement is true; the second statement is false.

The first statement is false; the second statement is true.

Both statements are true.

Both statements are false.

Both statements are true.

Health care workers have exhibited health problems from exposure to the following EXCEPT:

Mercury

Disinfectants

Latex gloves

Nitrous oxide

Fluorescent lighting

Fluorescent lighting

Safety equipment in the dental office should include the following EXCEPT:

A fire extinguisher

GFI outlets

Steel-toed shoes

Neoprene (rubber) gloves

Eye protection

Steel-toed shoes

Several chemicals used in the dental office penetrate latex gloves. Information on the proper protective gloves may be found in the SDS.

The first statement is true; the second statement is false.

The first statement is false; the second statement is true.

Both statements are true.

Both statements are false.

Both statements are true.

Surface disinfection occurs after an intermediate-level disinfectant is sprayed onto a surface and allowed to air-dry. Disinfection, however, is not effective unless the surface is first cleaned.

The first statement is true; the second statement is false.

The first statement is false; the second statement is true.

Both statements are true.

Both statements are false.

Both statements are true.

The most hazardous form of mercury encountered in a dental office is:

Mercury vapor

Liquid mercury

Dental amalgam

Amalgam scrap

Mercury vapor

What is the recommended time to be serologically tested for antibody response after receiving the 3-dose series of hepatitis B vaccine?

1 to 2 days

1 to 2 weeks

1 to 2 months

1 to 2 years

1 to 2 months

What type of PPE must be worn while treating a patient with a highly infectious disease, such as tuberculosis, spread by aerosol?

Full face shield with a standard mask

Full face shield

HEPA mask

Standard face mask

HEPA mask

Which of the following does not contribute to musculoskeletal problems?

Which of the following does not contribute to musculoskeletal problems?

Poor lighting

Poor posture

Indirect vision

Repetitive motions

Indirect vision

Which type of patient care glove is recommended for noninvasive intraoral procedures?

Sterile surgeon's

Nonsterile exam

Copolymer "overgloves"

Utility gloves

Nonsterile exam

Which type of protective glove should be worn when hand scrubbing contaminated instruments before sterilization?

Exam gloves

Overgloves

Utility gloves

Sterile surgeon's gloves

Utility gloves

Identify the type of gloves that are used during cleaning and processing of instruments.

Surgeon's gloves

Utility gloves

Overgloves

Exam gloves

Utility gloves

Identify the period in which Ebola virus symptoms may appear after it is contracted.

2 to 21 days later

30 days later

7 to 10 days later

14 to 28 days later

2 to 21 days later

Intermediate-level disinfectants must meet all of these criteria EXCEPT:

Bacteriostatic

Virucidal

Tuberculocidal

Registered with the EPA

Bacteriostatic

Name the type of gloves that are nonsterile and are used for procedures that are noninvasive.

Exam gloves

Surgeon's gloves

Overgloves

Utility gloves

Exam gloves

Of the vaccines recommended for health care professionals, which one should be readministered every 10 years?

Varicella

Tdap

HBV

Influenza

Tdap

Semicritical objects are those that contact, __________, mucous membranes.

And penetrate

And only slightly penetrate

But do not penetrate

But do not touch

But do not penetrate

Standard precautions requires that: Patients with alerts on their medical histories be treated as potentially infectious.

All patients and materials be treated as potentially infectious.

All patients be treated as infectious, and only materials known to have been used are treated as potentially infectious.

Patients be treated as infectious on a case-by-case basis.

All patients and materials be treated as potentially infectious.

Which is NOT an indication for wearing eye protection?

When aerosols are likely

During any patient treatment

When indicated by the doctor

When projectiles may be generated

When indicated by the doctor

Which is the three-dose vaccine series that health care workers should have to minimize risk of the transfer of pathogens?

Varicella

Tdap

Hepatitis C

Hepatitis B

Hepatitis B

__________ objects must be heat sterilized in steam, dry heat, or saturated chemical vapor.

All

Semicritical

Noncritical

Critical

Critical

Dental prostheses should be stored in a __________ environment and never allowed to __________ as they may __________.

Wet, dry out, distort

Cool, dry out, discolor

Wet, heat up, distort

Warm, cool fully, discolor

Wet, dry out, distort

Grinding and polishing may be done:

After the appliance has been sterilized

Once the appliance has been disinfected

Immediately after the patient removes the appliance from the mouth

After gloves are donned and prior to the placement of a mask

Once the appliance has been disinfected

Heat sterilization is necessary for each of the following items EXCEPT:

Glass mixing slabs

Rubber mixing bowls

Rag wheels

Metal spatulas

Rubber mixing bowls

How often should the dental lathe be cleaned and disinfected?

Daily

Weekly

After every use

When it is visibly soiled

Daily

Metal prostheses soaked in __________ solution may become damaged.

Water

Ultrasonic

Disinfectant

Hypochlorite

Hypochlorite

The primary goal of an infection control plan is to prevent cross-contamination between:

Dental care providers and dentists

Dental care providers and office staff

Patients and other patients

Patients and dental care providers

Patients and dental care providers

What organization regulates the transport of contaminated items between the dental office and the laboratory?

OSHA

ADA

CDC

ANSI

OSHA

Which is NOT an appropriate method for cleaning a prosthetic appliance?

Clean, soft toothbrush

Denture brush

In an ultrasonic unit using a cassette

In an ultrasonic using a zippered bag or glass beaker

In an ultrasonic unit using a cassette

Which piece of equipment is NOT required when polishing dentures?

Proper room ventilation

Fresh pumice

Face shield

Mask

Face shield