Question 1

The x-ray was discovered on November 8,1895,by:

Accepted Answer

The x-ray was discovered on November 8, 1895, by Wilhelm Conrad Roentgen, a German physicist.

Question 2

Which of the following statements is true concerning the structure of the atom?

Accepted Answer

The statement that is true concerning the structure of the atom is that the orbital path of an electron around the nucleus is called an electron shell. The other statements are incorrect. The nucleus of an atom contains protons and neutrons, not electrons (A). Electrons do have mass, although it is very small (B). Electrons do have a specific and stable orbit around the nucleus, but they can move from one energy level to another (D).

Question 3

Which of the following structures will appear radiopaque on dental x-ray film?

Accepted Answer

Metal restorations, such as dental fillings, crowns, and bridges, will appear radiopaque on dental x-ray film because they are denser and absorb more radiation than surrounding tissues. Soft tissue, tooth decay, and dental pulp will appear radiolucent (transparent) or less dense on x-rays.

Question 4

The range of shades of gray between black and white on an image is called:

Accepted Answer

Contrast refers to the difference in brightness between the darkest and lightest parts of an image, and specifically relates to the range of shades of gray present.

Question 5

The dentist who is credited with the first practical use of radiographs in dentistry in 1896 is:

Accepted Answer

Edmund Kells is credited with the first practical use of radiographs in dentistry in 1896. While Roentgen discovered X-rays in 1895, Kells was the first dentist to see their potential for dental diagnosis and treatment.

Question 6

Damage caused by ionizing x-radiation to genetic cells:

Accepted Answer

Ionizing x-radiation can cause damage to genetic cells, which can affect future generations. This is why precautions are taken to minimize unnecessary exposure to radiation in medical and dental procedures. The other options are incorrect as radiation can affect more than just the person being X-rayed, and may damage cells in various areas of the body.

Question 7

The degree of density or blackness on an image is controlled by the:

Accepted Answer

The degree of density or blackness of an image is controlled by the milliampere seconds.
The low-voltage circuit lights the indicator light on the panel.
The kilovoltage controls the contrast.
The PID serves to direct the path of the x-ray beam.

Question 8

Which of the following tissues has the highest radiation sensitivity?

Accepted Answer

Small lymphocytes are highly sensitive to radiation due to their rapid cell division and turnover rate. This makes them more susceptible to radiation-induced DNA damage and cell death. Salivary glands and kidneys are also sensitive to radiation, but not as much as small lymphocytes. Muscle tissue is relatively radioresistant due to its lower cellular proliferation rate.

Question 9

One of the rules of radiation protection is to never stand closer than _____ feet from the x-ray unit during an exposure unless you are behind a barrier.

Accepted Answer

The recommended safe distance from an x-ray unit during exposure is typically 6 feet, as this distance helps minimize radiation exposure to personnel.

Question 10

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?

Accepted Answer

The guidelines state that necessary dental radiographs can be taken during pregnancy with appropriate shielding, as the benefits of diagnosing and treating dental issues outweigh the minimal risks associated with radiation exposure.

Question 11

Secondary radiation:

Accepted Answer

Secondary radiation refers to x-radiation that is created when the primary beam interacts with matter.

Question 12

A lead apron and a thyroid collar:

Accepted Answer

Lead aprons and thyroid collars are recommended for all patients during any dental radiographic procedure to minimize radiation exposure, regardless of the number of films or the patient's age or pregnancy status.

Question 13

Exposure to radiation:

Accepted Answer

There is no safe threshold for exposure to ionizing radiation. Any amount, no matter how small, has the potential to cause harmful biologic changes.

Question 14

The heart of the x-ray generating system is the:

Accepted Answer

The x-ray generating system consists of an x-ray tube which is the main component responsible for producing and emitting x-rays. The insulating oil and transformer are also important components, but they play a secondary role in the process. The position indicator device is not part of the x-ray generating system.

Question 15

_____ will improve the sharpness of a radiographic image.

Accepted Answer

Smaller film crystal size will improve the sharpness of a radiographic image. Smaller crystal size allows for greater detail and resolution in the image. Larger focal spot size, faster film, and movement of the patient can all result in decreased sharpness and clarity in the image.

Question 16

In dentistry,the _____ the wavelengths of the x-rays,the greater their energy and their usefulness.

Accepted Answer

Shorter wavelengths have higher energy and are more useful for dental imaging. They can penetrate through hard tissues like bone and teeth, allowing for better visualization of underlying structures. Longer wavelengths have less energy and are less capable of penetrating, making them less useful for dental imaging.

Question 17

The uses of dental images include the detection of:

Accepted Answer

The uses of dental images include the detection of bone loss in its early stages.
Incipient occlusal lesions are not usually visible on dental images and are detected with a dental explorer.
Periodontal probing depths cannot be determined by dental images and are detected with a periodontal probe.
Percussion sensitivity is not determined by dental images.It is usually detected with the end of the handle of a dental mirror.

Question 18

Anything that occupies space and has a form or shape is:

Accepted Answer

The definition given in the question matches the definition of matter, which is anything that has mass and takes up space. Energy does not have a form or shape, photons are a type of energy, and "solid" is an incomplete answer as not all matter takes the form of a solid.

Question 19

Which component of the x-ray machine functions in positioning the tubehead?

Accepted Answer

The extension arm is the component of the x-ray machine that functions in positioning the tubehead.

Question 20

The term _____ is used to describe areas that appear dark on the image; _____ is the term used to describe areas that appear white or light gray.

Accepted Answer

Radiopaque is used to describe areas that appear white or light gray on the image, while radiolucent is used to describe areas that appear dark. Density and contrast refer to the overall brightness and differences in brightness on the image, rather than specific areas. Therefore, the best choice is B, radiolucent for dark areas and radiopaque for light areas.

Quiz 38: Foundations of Radiography, Radiographic Equipment, and Radiation Safety