DNTA 1341 Q&A
One of the rules of radiation protection is never stand closer than ______ feet from the x-ray unit during an exposure unless you are behind a barrier.
6
What do increased exposure time settings result in?
A higher mAs value
This radiographic technique permits the imaging of one layer or section of the body while images of structures in other planes are blurred:
CBCT
Damage caused by ionizing x-radiation to genetic cells:
Can effect future generations
An example of cumulative radiation exposure is:
Cancer
Which of the following changes to your radiographic technique can lower patient exposure to radiation?Select all that apply.
Change from an 8 inch to 16-inch PID Start using a thyroid collar Change from D-speed to E-speed film
Which of the following shapes and sizes the x-ray beam?
Collimator
The correct order of steps in manual film processing is:
Develop, rinse fix and wash
Which of the following is a disadvantage of digital radiography over traditional film-based methods?
Digital sensors are bulky and uncomfortable
Which digital radiography technique uses intraoral sensors that send information to a computer for interpretation?
Direct Imaging
What is the purpose of the insulating oil that fills the x-ray machine housing and surrounds the x-ray tube?
Absorbs heat created by the production of x-rays.
Which of the following lists of dental materials is in order from most radiopaque to most radiolucent?
Amalgam - Enamel - Dentin - Pulp
Which of the following is a basic form of matter?
An atom
Which of the following is bombarded with electrons and releases x-rays?
Anode
What does the acronym ALARA stand for?
As Low As Reasonably Achievable
Which radiographic image depicts both the maxillary and mandibular arches in a biting position?
Bitewing
According to the test for x-ray film freshness, the film is fresh and has been properly stored and handled when the processed film appears clean with a slight ______ tint.
Blue
A step-down transformer is necessary within the x-ray circuitry to:
Boil off the electrons from the filament
The radiograph that you've just taken appears wrong somehow. It has very high contrast with very dark areas and very light areas, but little in between. How would you decrease the contrast if your X-ray unit has a full set of controls for you to adjust?
Increase the kVp to decrease the contrast
Increasing the milliamperage (mA) on the control panel will have what effect on the image produced?
Increased Dentisty
Your dentist wishes to convert her radiograph films to digital images for storage. Which technique(s) would be suited for that purpose?
Indirect imaging by scanning
Which of the following adjustments on the control panel controls the penetrating power of the x-rays produced?
KVP
A patient is concerned with radiation exposure. You can assure him that your office uses the ALARA concept, which includes:
Keeping exposure levels as low as possible
Ms. Jones bitewings turned out poorly due to the poor contrast of the radiographic image. Which of the following settings most impacts the contrast of an image?
Kilovoltage
A superthin sheet of ___________ is placed behind a piece of x-ray film for the purpose of reducing back-scatter of radiation.
Lead
What is the name of the protective cover that is placed on the patient from the neck to the lap area to shield sensitive tissues from scatter radiation?
Lead Apron
The safety device that restricts the diameter of an x-ray beam to 2.75 inches is called the:
Lead Collimator
Automatic film processing requires _____ than manual film processing does.
Less Equipment
Which of the following reduces patient exposure to x-radiation?
Longer PID
What does a higher kVp setting result in?
Lower contrast radiographs
The ALARA principle says that all exposure to radiation must be kept to the ________ amount possible that will still achieve the desired result.
Lowest
The largest dose of radiation that the body can endure with little or no injury is the:
Maximum permissible dose
All of the following structures will appear radiolucent on dental x-ray film except:
Metal restorations
Which of the following techniques can be used to reduce operator exposure to x-rays?
Move 6 ft from tubehead
The council that determines the radiation effects and levels tolerable for humans is the:
National Council on Radiation Protection and Measurements (NCRP).
Dental patient records must contain documentation of the ______ of dental images taken.
Number and type
Name the error that occurs when film is exposed to too much radiation or is left in the developing solution for too long, with the resulting image appearing dark.
Overexposed
This error occurs when the horizontal angulation of the beam is directed between the contacts of the adjacent teeth incorrectly:
Overlapping
What is another name for the right angle technique?
Paralleling technique
Who should hold the film in a patient's mouth if the patient is unable to do so?
Patient or relative of patient
The production and transmission of energy through space or a substance in the form of waves that penetrate matter is called:
Radiation
The Guidelines for Prescribing Dental Radiographs issued by the American Dental Association and the FDA recommend which of the following dental imaging procedures for a pregnant patient?
Radiographic imaging procedures do not need to be altered because of pregnancy.
Thermionic emission refers to the:
Release of electrons from the tungsten filament
Each of the following must be disclosed to the patient before obtaining informed consent for dental radiographs except one. Which one is the EXCEPTION?
Rights of the patient as owner of the images
Who can be held legally responsible for a dental assistant's actions?
The dentist
If you change the exposure time of the x-ray unit, what is affected?
The number of x-rays produced
Which of the following statements is true concerning the structure of the atom?
The orbital path of an electron around the nucleus is called an electron shell.
Which of the following statements about digital sensors is incorrect?
They can be heat sterilized with caution
What is the purpose of the aluminum filter in the x-ray tube?
To filter out long wavelength x-rays
ALARA means "as low as reasonably achievable" and indicates that radiographic techniques will be employed to reduce the amount of patient exposure to the lowest needed to get diagnostic image
True
Areas on the radiograph where x-rays hit show as dark regions that are called radiolucent.
True
Digital radiographs expose the patient to less radiation than traditional film-based systems.
True
Image contrast is related to the number of shades of gray that are represented.
True
Scatter radiation is produced when the primary beam is weakened and deviated in its path, thus interacting with patient body tissues.
True
The office manager ordered F speed film rather than the usual E speed film by accident. Would this explain why the series of radiographs on Ms. Smith turned out very dark?
True
The primary beam consists of the x-rays that emerge from the tubehead.
True
What is the name of the tightly sealed housing that holds the parts required to generate an x-ray?
Tubehead
When a daily radiograph is lighter than the reference radiograph, it indicates the developer is too:
Weak
The fuzzy or blurred area around an image is called _____________. It can be reduced by _______________.
a penumbra; limiting movement
The use of digital imaging includes the detection of:
abnormalities in surrounding hard and soft tissues.
Name the type of radiographic image that is produced with the use of conventional film:
analog
Positioning instruments in digital radiography:
assist in film placement and keep the patient's fingers from being exposed.
What is the most basic structure of matter, comprising the nucleus and electrons?
atom
In what method of obtaining a digital image is an intraoral sensor exposed to radiation to capture an image that is then displayed on a computer monitor?
direct digital imaging
The term image receptor refers to:
either a digital imaging sensor or to film.
The component of the x-ray machine that functions in positioning the tubehead is the:
extension arm
As long as the operator wears a lead apron, it is permissible for him or her to hold the film in place for the patient.
false
Phosphor storage plate systems have the advantage of requiring less radiation than direct digital systems and are preferred, as a result.
false
The exposure time is set by adjusting the collimator on the tubehead.
false
The removal of weak x-rays from the beam before it leaves the tubehead is the job of the collimator.
false
What is produced when electrons from the cathode impact the tungsten target on the anode?Select all that apply.
heat and x-rays
Loss of an electron from one of an atom's orbiting shells is called:
ionization
Which of the following determines the quantity of X-rays produced during an exposure?Select all that apply.
mA & exposure time
The degree of density or blackness on an image is controlled by the:
milliampere seconds
Which of the following terms is used to describe the energy or penetrating ability of the x-ray beam in dental radiography?
quality
Quality assurance in the dental office is a way of ensuring that everything possible is being done to produce high-quality diagnostic images and includes quality control:
tests and administration procedures.
The most commonly used film size for adult intraoral dentistry is size:
#2
The maximum safe operator exposure to x-rays at the workplace is what percentage of the patient's exposure limit?
0
The recommended distance between the safelight and where the films are unwrapped is:
4 ft
A _____________ badge is worn to show the degree of occupational exposure incurred by the wearer in a month.
Dosimeter
What happens when the exposure button on a dental x-ray machine is pressed?
Electrons slam against the target of the anode producing the x-ray.
Which error occurs when the vertical angulation is insufficient, resulting in the omission of the apexes of the teeth from the film?
Elongation
Using your knowledge of tooth structure, determine which substance would appear most radiopaque.
Enamel
If the operator's film badge indicates an exposure to small amounts of radiation, what should be done?
Evaluate the x-ray equipment and techniques
What control panel setting on most new x-ray units is responsible for determining the quantity of x-rays produced and therefore the density of the image?
Exposure Time
Which of the following film speeds reduces patient exposure to radiation the most?
F speed
The latent image in the digital sensor must be erased between each exposure so as not to create a double image. True
False
Your dental office is transitioning from using film to phosphor storage plates for obtaining patient radiographs. Mr. Hampton, with his small mouth and large mandibular tori, has always presented a challenge when it was time for imaging. How will the new system compare to the older film system in terms of patient comfort?
Film and PSP will feel the same to the patient
Clear spots on a processed film can be caused by:
Fixer contacts film prior to processing
In which chemical solution is film immersed to remove unexposed silver halide crystals?
Fixing
The location where x-rays are produced in the x-ray tube is called the:
Focal Spot
Which of the effects of radiation exposure are passed along to future generations?
Genetic Defects
Which of the following structures would appear radiolucent on a radiograph?
Gingiva
___________ radiation is less penetrating than primary radiation.
Secondary
In dentistry, the __________ the wavelengths of the x-rays, the greater their energy and their usefulness.
Shorter
All of the following are true statements about film badges except:
they should be worn when any form of x-ray is taken. (Not when you are getting x-rays taken!)
Rapid turnover of cells in a tissue is usually an indication that the tissue is sensitive to damage by ionizing radiation.
true
The removal of weak x-rays from the beam before it leaves the tubehead is the job of the aluminum filter.
true
Which of the following is not related to limiting patient exposure to x-radiation?
use of a film badge
A good protocol to follow for decreasing the contamination of dental imaging equipment if additional supplies are needed during a procedure is to:
use overgloves
