Radio 145 Final Flashcards
Who developed the first x-ray tube
Coolidge
Who discovered x-rays
Roentgen
Who expose the first dental radiograph
Walkhoff
What type of electrical charge does the electron carry
Negative
What describes ionization
Atom that loses an electron
Where are x-rays produced
In the negative cathode
Where does thermionic emission occur
Negative cathode
What describes primary radiation
Radiation that exits the tube head
What describes scatter radiation
Radiation that has been deflected from its path by interaction with matter
In general imaging what is the quality of the x-ray beam controlled by
Kilo voltage
What is the kilo voltage range for current dental x-ray machines
70 to 100 kV
What does a higher kilovoltage produce x-rays with
Greater energy levels, shorter wavelengths, more penetrating ability
Results from radiation produced with high kilovoltage
Short wavelengths
What is the milliamperage range used for current dental x-ray machines
6 to 8 mA
What is the overall blackness or darkness of an image
Density
If kilovoltage is decreased with no other variations in exposure factors, what will the resulting image look like
Appears lighter
What is the term that describes how dark and light areas are differentiated on an image
Contrast
The latent period In radiation biology is the time between
Exposure to x-radiation and clinical symptoms
Radiation injuries that are not seen in the person irradiated but that occur in future generations are termed
Genetic effects
What is most susceptible to ionizing radiation
Small lymphocyte
What is the sensitivity of tissues to radiation determined by
Cell differentiation, cell metabolism, mitotic activity
What is considered radio resistant
Mature bone cells
What is an organ that if damage diminishes the quality of life termed
Critical
What is the greatest contributor to artificial radiation exposure
Medical radiation
X radiation is not harmful to living tissues
False
Every patient should be evaluated individually prior to prescribing dental images
True
The thyroid collar must be worn for both intraoral and extra oral exposures
False
If necessary the dental radiographer may hold a receptor in the patient’s mouth to ensure a diagnostic image
False
What describes the function of a filter in a dental x-ray tube head
It removes low energy x-rays
What is the most effective method of reducing patient exposure to radiation
Fast films
Which position indicating device is most effective in reducing patient exposure
Rectangular
Which device restricts the size and shape of the x-ray beam
Collimator
Which material is used as a collimator
Lead
What is the recommended size of the beam at the patient’s face
2.75 inches
What term describes the dose of radiation that the body can door with little or no chance of injury
Maximum permissible dose
The radiation monitoring badge should be worn at waist level when exposing x-ray receptors
True
What are dental receptors place inside the mouth termed
Intraoral
What is the component part of the dental x-ray machine that contains the x-ray tube termed
Tube head
What is used to restrict the size of the x-ray beam to the size of an intraoral receptor
Collimating device
Why is the identification dot on the intraoral film significant
Indicates the patients right or left side, determines film orientation, is important in film mounting
What is one advantage of a film with an emulsion coating on both sides
The film requires less radiation exposure to make an image
What is the purpose of a lead foil sheet in the film packet
To protect the film from backscattered radiation
What is the largest intraoral film size
4
The portion of a dental image that appears dark or black is termed what
Radiolucent
What is the portion of a dental image that appears light or white termed
Radiopaque
What appears most radio Lucent on a dental image
Air space
What appears most radiopaque on a dental image
Enamel
The overall blackness or darkness of a dental image is termed what
Density
What do leaks of white light in the dark room cause
Film fogging
How many feet at minimum must a safe flight be placed from the film and work area
4
Why should unopened boxes of radiographic film not be stored in the dark room
Chemical fumes from processing solutions may fog the film
How often should the processing tank be cleaned
Whenever solutions are changed
For quality control purposes each new box of unopened film should be tested for film freshness and fogging before it is used
True
How will fresh film appear that has been stored properly after processing
Clear with a slight blue tint
What is the coin test used to check
Proper safe lighting
What is a reference radiograph used to check
Strength of the developer solution
What is the clearing test used to monitor
Fixer strength
Use of a chemical or physical procedure to destroy all pathogen’s including spores
Sterilize
Micro organisms capable of causing disease
Pathogen
Exposure to infectious materials resulting from the procedures performed by the dental professional
Occupational exposure
Exposure to infectious materials that result from piercing or puncturing the skin
Parenteral exposure
Use of a chemical or physical procedure to destroy all pathogen’s except spores
Disinfect
Instrument used to penetrate soft tissue or bone
Critical instrument
Waste that consists of blood blood products contaminated sharps and other microbiological products
Infectious waste
Absence of pathogen’s
Asepsis
What is the primary purpose of infection control
To prevent disease transmission
What are the three possible routes of disease transmission
Direct, indirect, airborne
What is the proper direction of the central ray in the bisecting technique
90° to the imaginary bisector
Describe the distance between the receptor and the tooth in the bisecting technique
The receptor is placed as close as possible to the tooth
What’s an advantage of the bisecting technique
Shorter exposure time
The disadvantages of the bisecting technique outweigh the advantages
True
What size receptor is recommended for use with the bitewing technique in the adult patient
Size 2
What size receptor is recommended for use with the bitewing technique in the pediatric patient with primary dentition
Size 0
How is the patient’s head position before exposing a bitewing receptor
Maxillary arch is parallel to the floor mid sagittal plane is perpendicular to the floor
What size receptor is used to include all of the posterior teeth in one bitewing exposure
Size 3
What type of angulation is determined by the up and down movement of the position indicating device
Vertical angulation
What type of angulation is determined by the side to side movement of the PID
Horizontal angulation
When the central ray of the x-ray is not directed through the contact areas of the teeth what error is seen on the resulting image
Overlapped contacts
When does it cone cut result
When the beam is not centered over the film the x-ray doesn’t hit the film
Too much vertical angulation results in images that are what
For shortened
To little vertical angulation results in images that are what
Elongated
Incorrect horizontal angulation results in images that are what
Overlapped
What errors can occur with the bitewing technique
Overlap contacts, cone cut
What errors can occur with the bisecting technique
Elongation, overlapped contacts, Cone cut, phalangioma
What describes a use of a panoramic image
Evaluation of impacted molars
What is the zone in which structures are clearly demonstrated on a panoramic image termed
Focal trough
Why aren’t thyroid collars recommended in panoramic imaging
It blocks the x-ray beam and obscures information
What imaginary plane passes from the bottom of the eyesocket through the top of the ear canal
Frankfort
What procedure has a collimator is a lead plate with the small round or rectangle or opening
Intraoral image
Procedure must earrings and necklaces be removed for
Panoramic imaging
Procedure requires the mid sagittal plane to be positioned perpendicular to the floor
Panoramic and intraoral imaging
During which procedure must the vertebral column be perfectly straight
Panoramic imaging
In digital imaging the term used to describe the picture that is produced is radiograph
False
Digital imaging requires more x-radiation than conventional radiography
False
The x-radiation source used in most dental imaging systems is a conventional dental x-ray unit
True
All intraoral sensors can be heat sterilized after use
False
One advantage of a digital imaging system is the superior grayscale resolution that results
True
The manipulation of the original digital images can be considered a legal issue
True
When was digital imaging introduced to dentistry
1987
What can digital imaging be used for
Detecting conditions of teeth and surrounding structures, evaluating the growth and development of jaws, confirmation of suspected disease
Why does digital imaging require less radiation then conventional radiography
The sensor is more sensitive to x-rays
The image receptor found in the intraoral sensor is termed what
CCD
What restorative material is least radiopaque
Acrylic
Describe the difference between a gold crown and a stainless steel crown as viewed on a dental image
Gold crowns are large radiopaque with smooth contours and regular borders stainless steel is thin less radiopaque with some see-through areas
What’s the difference between gutta Percha and silver points as viewed on a dental image
Gutta Percha is less radiopaque silver points are highly radiopaque
