UNIT II & III X-ray REVIEW

what films are extra-oral films

Panorex, Cepholometric, Orthopantomograph

importance of operator standing behind lead shield when exposing x-rays is to prevent being exposed to

Secondary, Direct, Scatter, and Leakage radiation

at what age is the 1st radiographic survey on child

age 3

what happens when you sterilize

all forms of microorganisms have been destroyed

what prevents weak radiation leaving tube during exposure

aluminum filter

procedure regarding immersion disinfection

any instruments added to solution before disinfection time is up you must start timing all over

what is ION

atom that has lost an electron

why is radiation considered harmful

because it is cumulative

what x-rays show interproximal and are cavity detecting radiographs

bite wing x-rays (BWX)

material responsible for giving support & stiffness to x-ray film

cellulose acetate

an extra-oral film that shows a lateral view of the skull is

cephalometric

distortion

changes in shape or size of object

what is reticulation

cracking of film emulsion due to excessive heat during processing

when using ultra speed film would you increase or decrease exposure time

decrease

Radiolucent

degree of darkness on a film

what is the negatively charged particle that is responsible for producing dental radiographs

electrons

what stops the developing agents

fixer

what causes films to turn brown and discolor after a few days

improper washing

where is the thermometer placed

in the water tank

what causes overlapping

incorrect horizontal angulation

four body tissues most sensitive to radiation

intestinal tissue, embryo, cornea of the eye, bone marrow

speed of electrons through a circuit is referred to as

kilovoltage (KV)

radiation protection for pt.

lead apron (NOT LEAD SHIELD)

how is collimation accomplished

lead washer

what is a good anatomic landmark to look for when mounting an upper bicuspid film

maxillary sinus

Instrument from XCP kit that allows operator to align PID at the right angle to the film and long axis of the tooth is the

metal indicator rod

cathode

negative terminal

why dental mask is worn

protect mucous membrane of nose & mouth

the value of radiographs for Pt. education includes

results in missing teeth, implants/ bridges from restored mouths, results in reconstructive surgery, orthodontic conditions

what is radiopaque

shows white on then film

substance found in emulsion of film that is responsible for an x-ray

silver halide crystals

what causes cone cutting

the center of the primary beam was not directed to the center of the film

what part of the x-ray machine produces radiation

the tube

what is density

thickness of an object being radiated

what is the purpose of the lead foil of a film packet

to prevent secondary radiation from fogging film

what causes foreshortening

too high a vertical angle

besides gamma rays, what additional radiation wave from the EMR spectrum is considered harmful to tissue due to its wavelength

ultraviolet

know why ultrasonic cleaner is preferred to hand scrubbing

uses sound waves to reach all areas of the instruments, uses cavitation process, safer for the auxiliary

what is considered radiation protection for operator during Pt. exposure

6-8ft distance from tube, lead shield, double walled gypsum board

how much radiation reduced by using Ultra Speed film

85%

contrast

Diff. betw. black, white, & shades of gray

hat is occupational dose limits for radiation exposure in a calendar quarter (13 wks.) for the whole body

1.25 REMS

what is the target distance for the paralleling technique

12-16 inches

full mouth x-ray for an edentulous Pt. would include

14 PA's no BWX

exposure to edentulous Pt. can be reduce by

25%

minimum allowable distance of the dark room safety light from the working counter top

4ft.

who can legally expose x-rays described by "California Law"

DA who passes board approved course and receives x-ray certificate. at least 18yrs of age