Midterm Midterm Test Questions

Question 1

What adjustment is made to control the contrast of an xray image?

Answer 1

kVp

Question 2

How does a PSP xray film capture an image?

Answer 2

it stores the xray in a phosphor plate which is scanned

Question 3

What is the main advantage of using PSP xray films over traditional xray films?

Answer 3

it reduces the radiation dose needed

Question 4

How is a PSP xray film erased?

Answer 4

exposing it to visible light

Question 5

Structures that radiation can easily pass through appear ____ on an image

Answer 5

radiolucent

Question 6

what is the purpose of the aluminum filter within the tube head?

Answer 6

remove the low energy long wavelength xrays from the beam

Question 7

Shorter wavelength xrays have a higher penetrating power- true of false?

Answer 7

True

Question 8

Which of the following is a common drawback of direct digital sensor?

Answer 8

Hard & rigid in patients mouth - can be hard to plce

Question 9

What is the function of CMOS sensor?

Answer 9

CMOS sensors convert X-ray photons into an electrical signal using an array of photodiodes and amplifiers. The direct digital CMOS sensor senses radiation and automatically saves the image with date, correct orientation, and tooth numbering. The images are available at once, removing the time hitherto spent on developing and setting up traditional x-rays.

Question 10

Which of the following conditions can be diagnosed using PA

Answer 10

Bone loss & Root infections

Question 11

What type of dental issues can be detected using a panoramic issues?

Answer 11

impacted teeth, jaw fractures, cysts

Question 12

A properly exposed PA xray should show?

Answer 12

the entire tooth, crown and root and surrounding bone

Question 13

Which imaginary plane passes from the bottom of the eye socket trhough the top of the ear canal?

Answer 13

The Frankfort plane

Question 14

What is the average radiation dose of a dental xray?

Answer 14

0.005 mSv

Question 15

What factors affect the penetration power of the radiation?

Answer 15

Density of object, distance, wavelength

Question 16

What is the main difference between genetic & somatic effects?

Answer 16

somatic - individual
genetic - future generations

Question 17

What effects the quantity and quality of xray beam?

Answer 17

Milliamperage & Kilovoltage

Question 18

How to answer..

I realize I’m experiencing tooth pain and sensitivity, but do I really need all those x-rays? I heard that dental x-rays are dangerous and cause cancer. Is that true?

Answer 18

The DDS requires radiographs to do a complete comprehensive exam/thorough diagnosis.

Ionizing radiation can be harmful…esp in high doses and long duration.

BUT PSP is a form of digital imaging that requires very little radiation.

We also follow a required safety measures ie: monitor equipment, lead aprons

Question 19

Dr. Sait suggested that you take periapicals and bitewings. What is the difference and do I need to have both types taken?

Answer 19

Periapical is a specific xray that show the entire tooth (root tip-crown) & supporting structures.

Bitewings – show max and mand crowns and bone level and are primarily used to detect cavities in between the teeth and to assess bone levels.

Both types are required for the exam today because the DDS will use both types for an accurate diagnosis.

PA’s are typically used for specific concerns (cold sensitvity, swelling, pain etc..)

BW’s are used for an overall exam of all quads to look for decay that cannot be seen in between the teeth.

Question 20

Dr. Sait completes an initial visual exam, she would like you to expose a quad 1 molar periapical, a 3.3 periapical, a quad 3 premolar periapical and 4 bitewings using the PSP method.

collect the supplies you will require to expose the requisitioned images. What will you get?

Answer 20

XCP kit – posterior PA, anterior PA, bitewing

6 - Size 2 PSP plates, 1-size 1 PSP plate

Question 21

Before you start the procedure, Sandra is looking a bit nervous. She asks you to explain the steps of exposing a periapical.

Answer 21

***set control panel first

Sit upright

Lead apron/heavy!

Position receptor in mouthline up PID

Hold still

Beep

Remove from mouth

Will do it 3 x and 4 bitewings

Question 22

Because of your knowledge and skill, all 3 periapical images are diagnostically acceptable!!! What are the characteristics of a diagnostically acceptable periapical?

Answer 22

Contrast, magnification, sharpness, all required anatomy visible

Question 23

Identify the teeth that will be present in all 4 bitewings. The patient has a complete dentition.

Answer 23

Right side posterior – 1.8-1.6 & 4.8-4.6

Right side premolar – 1.3 (distal) -1.6 (mesial) & 4.3(distal) – 4.6 (mesial)

Left side posterior – 2.8-2.6 &.3.8-3.6

Left side premolar – 2.3(distal) – 2.6(mesial) & 3.3(distal)-3.6(mesial)

Question 24

You process the bitewing images and the right side premolar image is not diagnostically acceptable because the contacts are not open. Describe what closed contacts look like on an image and how can this be corrected.

Answer 24

Closed contacts have overlap. No space between teeth and unable to detect interproximal cavities.

Adjust horizontal angulation to make sure the central ray is directed through the contacts.

Question 25

Jim asks “What is produced by the x-ray machine in a dental office?” You tell him it produces:

Answer 25

photons

Question 26

Jim says he read about x-ray tubes and knows that the negative electrode, or cathode, is the source of electrons to generate x-rays. He asks you to explain how photons, which have no mass, could be produced by the x-ray machine when it is true that the cathode produces electrons. You explain to Jim that the ____________ converts bombarding electrons into x-ray photons.

Answer 26

tungsten target in the anode

Question 27

Jim knows that the line voltage in a building is either 110 or 220 volts and asks you, “How much voltage is used to generate the x-rays in the x-ray tube?” You tell him it is ____ volts.

Answer 27

65,000 to 100,000

Question 28

Jim asks, “Which part of the x-ray machine is capable of creating 100,000 volts?” You explain that the ______________ in the x-ray machine accomplishes this task.

Answer 28

transformer

Question 29

Finally, Jim asks you to explain what happens to the photons when they arrive at the patient, and you tell him that a majority of the photons:

Answer 29

collide with a loosely bound outer-shell electron and give up part of their energy to eject the electron from its orbit. The x-ray photons then lose energy and continue in a different direction and interact with other atoms until all their energy is gone.

Question 30

Jim is curious about the science one must know and understand prior to studying radiation in dentistry. You tell him:

Answer 30

The physics of the atom

Question 31

You feel Jim needs to understand the difference between radiation and radioactivity so you explain:

Answer 31

Radiation is the emission and propagation of energy while radioactivity is the process by which atoms or elements decay.

Question 32

Proofing his science paper, you notice that he states communication media uses high-frequency, longer waves in the electromagnetic spectrum. You tell him:

Answer 32

Communication media uses low frequency, longer wavelengths.

Question 33

Jim asks, “The conversion of electrons to x-ray photons is confusing. Can you explain it to me?” You respond, “The electrons most often have __________ with the tungsten atoms in the anode target, producing __________ radiation.”

Answer 33

many interactions; braking

Question 34

Jim is concerned that, from what he has read, scatter radiation is a problem for the dental professional. You explain that there are two types of scatter radiation. The Compton scatter accounts for ____% of scatter that occurs in diagnostic radiography.

Answer 34

62

Question 35

She wants to know if radiation can cause cancers, and you tell her that:

Answer 35

all ionizing radiations are harmful and produce biologic changes in living tissue.

Question 36

She asks you to tell her how much radiation she receives each year as background radiation just as a part of living her life. You tell her the average dose of background radiation received by an individual is ___________ millirads per year.

Answer 36

150 to 300

Question 37

You tell your friend’s mother that the risk of cancer from dental radiography is approximately 3 in 1 million, which is much less than the risk of spontaneously developing cancer. She seems somewhat taken aback, so you tell her that a 1 in 1 million risk of a fatal outcome is about the same as for riding _____ miles in an automobile.

Answer 37

300

Question 38

She has heard that she could get leukemia from dental x-rays and asks if that is true. You explain:

Answer 38

The dose of radiation necessary to produce leukemia isn’t anywhere near what occurs in dental imaging.

Question 39

Further concerned, she asks, “Isn’t there any new development in dental science that will reduce a patient exposure to radiation, and you too?” You tell her, “Yes there is. It is called ______________.”

Answer 39

digital imaging

Question 40

Finally, she asks how a dental professional decides what x-rays to proscribe. You tell her that when x-rays are properly prescribed and exposed, the benefit of __________far outweighs ____________.

Answer 40

disease detection/risk of biologic damage

Question 41

Jimmy’s mother suggests that you hold the film in Jimmy’s mouth while she makes the exposure. You tell Jimmy’s mother that:

Answer 41

the dental radiographer must never hold the film in place for a patient during x-ray exposure.

Question 42

Jimmy wants to know why you want to put the heavy “blanket” (lead apron) on him before taking his “pictures.” You explain that:

Answer 42

“It works to limit excessive radiation.”

Question 43

Jimmy turns his head to watch you leave the room, which changes the alignment of the tubehead with the receptor. As you remind him to look straight forward, you tell Jimmy’s mother that you are trying to avoid:

Answer 43

retaking the image.

Question 44

Jimmy’s mother asks you to tell her how much radiation a dental professional can be exposed to in a year. You tell her that the current maximum permissible dose (MPD) for occupationally exposed persons is ___ Sv/year.

Answer 44

0.05 Sv/year
(50 mSv/year)

Question 45

Following your explanation of the types of dental images you will be taking on Jimmy, his mother asks, “Is he required to have those every 6 months?” You tell her:

Answer 45

“If we can see between his teeth, we will use our clinical judgement as we monitor for growth and development.”

Question 46

From an appropriate distance, Monica observes her son wiggling during one of the exposures and asks, “Aren’t you going to retake that one?” You reply:

Answer 46

“Possibly, but we will develop the image to be certain. We avoid retaking images.”

Question 47

Jimmy asks why you go so far away to “click the button.” You tell him that to prevent x-rays from taking your picture too, you must be at least ____ feet away from the x-ray tubehead.

Answer 47

6

Question 48

Anne tells you that while reading her textbook last night, she learned that the kilovoltage peak (kVp) can be defined as the maximum or peak voltage. When she asks you what that means with respect to the beam of photons that exit the x-ray machine, you tell her that the:

Answer 48

quality, or wavelength and energy of the x-ray beam is controlled by the kilovoltage peak. It determines the penetrating ability of the x-ray beam.

Question 49

Anne then asks you to explain how milliamperage differs from kilovoltage. “If kilovoltage determines the quality of the x-ray beam, then what property of the x-ray beam does the milliamperage control?”

Answer 49

the quantity of photons that exit the tubehead

Question 50

Anne tells you that although she understands that density is the overall darkness or blackness of an image, she does not grasp what contrast represents. You tell her that contrast refers to:

Answer 50

how sharply dark and light areas are differentiated or separated on an image

Question 51

You ask Anne to describe the inverse square law. She responds, “The intensity of radiation is inversely proportional to the square of the distance from the source of radiation.” You respond,

Answer 51

“You are correct!”

Question 52

You ask Anne, “To what does the quality of an x-ray beam refer?” She correctly responds:

Answer 52

“The energy, or penetrating ability of the x-ray beam.

Question 53

You ask, “If quantity refers to then number of x-ray photons and quality refers to the energy of each photons, then what is intensity?” Anne answers: “Intensity is defined as the product of the quantity (number of x-ray photons) and quality (energy of each photon) per unit of area per unit of time of exposure.” You respond:

Answer 53

You are correct!

Question 54

You ask Anne, “If you were to increase the milliamperage setting, what effect would it have on a dental image?” She responds correctly

Answer 54

It would darken the image.

Question 55

You ask her to name the three characteristics of radiation. Anne replies, “Quality, quantity, and intensity.” You tell her:

Answer 55

You are correct!

Question 56

Kim asks how she will be able to tell that an exposure has been made, and you tell her the exposure light turns ______ and the beep ______ when the x-ray exposure is completed.

Answer 56

off; stops

Question 57

Kim says that she always thought the patient held the dental x-ray film in position using a finger, and you tell her a __________ is a device used to hold and align intraoral dental x-ray films in the mouth.

Answer 57

film holder

Question 58

Kim asks you what you are using as a film holder, and you tell her that you are using a Stabe Bite-Block, which is a:

Answer 58

disposable Styrofoam bite-block.

Question 59

After several films have been processed, one of the supervisors tells you that a few of the images are light. You know that the exposure times were set properly, and a quick check reveals the films have not been placed backward, so you suggest to Kim that she:

Answer 59

makes sure she holds the button down until the end of the beeping sound.

Question 60

Noticing a small certificate affixed to the x-ray machine, Kim asks, “Has this thing been repaired, or what?” You assure her, “No, that is the registration certificate showing the x-ray machine has been inspected and monitored, which our state requires.” Prior to ___________, however, no federal standards existed for the manufacturer of dental x-ray machines.

Answer 60

1974

Question 61

Kim is thinking of volunteering with the dental students at a local nursing home. She wonders how they will get dental images on the residents. You tell her:

Answer 61

Some intraoral units are portable and allow for exposures outside of the dental office in sites such as nursing homes and mobile clinics.

Question 62

In order to use the digital imaging system, the office will need:

Answer 62

a computerized imaging system.

Question 63

Which of the following is/are true of a system using a CCD?

Answer 63

The CCD is an image receptor found in the intraoral sensor

Question 64

The typical exposure time required to produce an image for digital imaging is __ impulses.

Answer 64

3

Question 65

The CCD:

Answer 65

contains a silicon chip with an electronic circuit embedded in it.

Question 66

For infection control purposes, the CCD sensor:

Answer 66

must be covered with a disposable barrier or sleeve.

Question 67

One of the topics discussed is radiation exposure. You learn that exposure times for digital imaging are ____________than those for conventional radiographic imaging.

Answer 67

50-90% less

Question 68

The first intraoral film container you examine contains size 1 periapical film. This size film is used primarily to examine:

Answer 68

anterior teeth in adults.

Question 69

Some of the film is D-speed film, some is E-speed film, and the rest is F-speed film. Which of the following statements is true concerning these film speeds?

Answer 69

Use of current F-speed films will reduce the radiation dose to the patient in comparison with that from D-speed films.

F-speed film requires 60% of the exposure time of D-speed film and has comparable image contrast and resolution. F-speed film is a faster film because of larger halide crystals and an increased amount of silver bromide in the emulsion. The American Dental Association (ADA) and the AAOMR currently recommend the use of F-speed film.

Question 70

Which of the following film sizes is appropriate for panoramic imaging?

Answer 70

5 × 12-inch film

Question 71

Some of the film in the provided supply is duplicating film. Duplicating film differs from intraoral or extraoral film in that:

Answer 71

duplicating film has an emulsion on one side of the film only.

duplicating film is not exposed to x-rays.

Duplicating film has an emulsion on one side only. The emulsion side of the film appears dull, whereas the side without the emulsion appears shiny. Unlike intraoral and extraoral films, duplicating film is used only in a darkroom setting and is not exposed to x-rays.

Question 72

Duplicating film should be stored and protected:

Answer 72

in areas that are adequately shielded from radiation.
in a cool, dry place.

Question 73

To demonstrate the different layers of a film packet, you open one for the students to view. There are four component parts to a dental film. The piece of flexible polyester plastic is called the ________________.:

Answer 73

film base

Question 74

On close inspection of the opened film packet, students notice a thin layer attached to both sides of the film. This is the _____________.

Answer 74

adhesive layer

Question 75

Students know that gelatin is used to suspend and evenly disperse silver halide crystals over the film base, but they are unsure what it provides. You tell them that

Answer 75

it absorbs processing solutions
it allows chemicals to react with silver halide crystals

Question 76

Students want to know which films are advised when the interproximal spaces need to be closely evaluated?

Answer 76

bitewing

Question 77

Students ask, “During development, what happens to a latent image? Does it go away? Can we simply not see it any longer?” You tell them

Answer 77

“It becomes visible.”

Question 78

How are photo-stimulable phosphor imaging (PSP) images captured?

Answer 78

PSP plates are coated with the phosphors. These phosphor crystals capture and hold the latent image until it is processed.

Question 79

What is a latent image?

Answer 79

A transposed image which is not visible until it is processed

Question 80

Is PSP a digital or non-digital method of exposing radiographs?

Answer 80

Digital

Question 81

Are PSP plates disposable or reusable?

Answer 81

REUSABLE

Question 82

Can PSP plates be sterilized?

Answer 82

NO - have barrier around them. which is wiped, disgarded, replaced.

Question 83

Is there more radiation exposure to the patient using the PSP method or the traditional film method

Answer 83

Traditional film has more radiation exposure to patient

Question 84

How long does it take the laser scanner to scan the PSP plates and produce an image to the computer screen?

Answer 84

30 seconds to 5 minutes

Question 85

How are PSP plates stored?

Answer 85

PSP plates should be packaged before use and kept away from ambient light as it can degrade the image

Question 86

What 3 essential components are needed for a direct digital imaging system?

Answer 86

an x-ray machine
an intraoral sensor
a computer/monitor

Question 87

How are direct digital images captured?

Answer 87

a fiber optic cable runs from the sensor directly to the computer
once the image is captured it is immediately delivered to the computer

Question 89

Is there more radiation exposure to the patient using the direct digital method or the conventional method?

Answer 89

conventional method

Question 90

How long does it take for the sensor to capture the radiographic image and transmit the image to a computer monitor - for digital?

Answer 90

seconds

Question 91

How are direct digital sensors stored?

Answer 91

They should be hung up so the cord is not dangled and cannot be damaged or bent.

Question 91

What are the components of an intraoral dental traditional xray film?

Answer 91

1. Waterproof outer package
2. Black paper
3. Film
4. Black Paper
5. Lead foil backing
6. Waterproof outer package

Question 92

What size of film would you use for..an adult bitewing xray?

Answer 92

Size 2

Question 92

what is the function for each layer of the dental film?

Answer 92

1. Waterproof outer package - protects the film from saliva and exposure to light
2. Black paper - Shields/protects the film from light
3. Film - where the image is produced
4. Black paper - shields/protects the film from light
5. Lead foil backing - shields the film from secondary radiation that results in film fog
6. Waterproof outer package - Protects the film from saliva and exposure to light

Question 93

What size of film would you use for… a bitewing xray taken on a child?

Answer 93

Size 0 or 1

Question 94

What size of film would you use for… a PA xray taken for an adult molar?

Answer 94

Size 2

Question 95

What size of film would you use for.. an occlusal xray for a child?

Answer 95

size 2

Question 96

What size of film would you use for…. a PA xray for an adult anterior tooth?

Answer 96

size 1

Question 97

What size of film would you use for… an occlusal xray for an adult?

Answer 97

size 4

Question 98

Who is Dr. Edmund C. Kells?

Answer 98

Dr. C. Edmund Kells, a New Orleans dentist, is credited with the first practical use of radiographs in dentistry, in 1896 Kells, after years of exposing his hands to X-rays every day, eventually lost his fingers, hand, and later his arm as a result of cancerous tumors.