Radiation Physics (ch 2)
What is the smallest fundamental unit of matter?
Atom
In digital imaging, a receptor that is used to capture an intraoral or extraoral image is the ______?
Sensor
This curvature of the occlusal plane extends from the incisor to the molars and is convex in the maxilla and concave in the mandible.
Curve of Spee
This common error occurs when there is excessive vertical angulation, causing the image to appear compressed
Foreshortened
What is the name of the bone that supports and encases the roots of teeth?
Alveolar bone
What portion of the x-ray machine suspends the tubehead and houses the electrical wires that extend from the control panel to the tubehead.
The extension arm
What are two examples of a beam alignment device?
XCP kit
Bite block
Aiming ring
Snap-a-ray
This method of mounting radiographs views the films as if you are looking at the patient, and is the ADA-recommended method.
Labial mounting
In the bisecting technique, the central ray must be directed perpendicular to this image line
Imaginary bisector
What size of sensor is typically used on patients with primary dentition?
Size 0
What type of radiation makes up about 70% of the x-rays produced in the dental x-ray tube and occurs when high-speed electrons are deflected by the tungsten nucleus?
General radiation
What are the 2 most popular types of direct digital sensor technology?
Charge-coupled device (CCD)
Complementary metal oxide semiconductor (CMOS)
These four pieces of information must be labeled on each film mount: the patient’s name, the date of exposure, the dentist’s name, and _____?
Radiographer’s name
In the exposure sequence for the bisecting technique, these teeth should always be exposed first because they are easier for the patient and help them adjust to the process
Anterior teeth
If there is overlap that progressively gets worse as you move distally in the radiograph, is the overlap from the mesial or the distal?
From the mesial
What substance inside the tubehead absorbs the heat produced during x-ray production?
Insulating oil
Give one advantage and one disadvantage of digital imaging
Advantages: Superior gray-scale resolution, reduced exposure to x-radiation, increased speed of image viewing, lower equipment & film cost, increased efficiency, enhancement of diagnostic image, effective patient education tool, and eco-friendly
Disadvantages: initial set up costs, image quality, sensor size & thickness, infection prevention, wear & tear, and legal issues
Although dental hygienists may interpret radiographs, this dental professional has the legal responsibility for the final interpretation.
Dentist
One advantage of the bisecting technique is that it eliminates the use of this piece of equipment
Beam alignment device
For bite-wing exposure, when using the paralleling technique, the recommended vertical angulation of the x-ray beam is ____ ?
+10 degrees
What type of radiation occurs when a high-speed electron dislodges an inner-shell electron from the tungsten atom and causes ionization of that atom.
Characteristic radiation
What sensor sizes are used for direct digital imaging?
1 (1 inch)
2 (1/2 inch)
0 (1/3 inch)
To prevent damage and contamination, radiographs should always be held this way.
By the edges, with clean, dry hands
The bisecting technique is based on this geometric principle that states two triangles are equal if they share a common side and have two equal angles.
Rule of isometry
In a patient with an edentulous space or a prominent bony growth, the standard bitewing technique must be modified. Give one modification.
Use a larger receptor size
Adjust the angulation
Use a cotton roll to properly place the receptor