71 terms

Dental Radiography Exam 1

Chapters 6,27,16,17,19,18,21,27,15,7,9
three components of xray machine
tubehead, extension arm, and control panel
four components of xray film
film base, adhesive layer, film emulsion, and protective layer
________ in film emulsion absorb the x-radiation during xray exposure and store the energy from the radiation
silver halide crystals
invisible pattern on emulsion
latent image
three types of film used in dental radiography
intraoral film, extraoral film, duplicating film
intraoral film sizes
0,1,2,3,4--larger the number, larger the size
intraoral film speeds
D, F......f speed film reduces patient exposure to radiation by 60% compared with d speed
__________ transform xray energy into visible light, which in turn exposes the screen film
intensifying screens
special type of photographic film used to make an identical copy of an intraoral or extraoral radiograph
duplicating film
5 steps in film processing
development, rinsing, fixation, washing, and drying
chemical solution used in development process to reduce the exposed, energized silver halide crystals
developer solution 4 basic ingredients
developing agent, perservative, accelerator, and restrainer
fixer solution 4 basic agents
fixing agent, preservative, hardening agent, and acidifier
disease transmission may occur as a result of
direct contact with pathogens in saliva, blood, respiratory secretions, lesions...indiret contact with contaminated objects or instruments....direct contact with airborne contaminants present in spatter or aerosols or oral and respiratory fluids
3 conditions for infection control to occur
susceptible host, pathogen with suffiencient infectivity and numbers to cause infection
minimum ppe's
protective attire, care of hands
film is placed in mouth, parallel to long axis of tooth, central ray is directed perpendicular to film and long axis of tooth
paralleling technique
anterior teeth film size
posterior teeth size film
5 basic rules of paralleling technique
film must cover prescribed area, film positioned parallel to long axis of tooth, central ray directed perpendicular to film and long axis of tooth, central ray directed through contact areas between teeth, and xray beam centered over film to ensure all areas of film are being exposed
which teeth should you always start with in paralleling technique
advantages of paralleling technique
produces images with dimensional accuracy,simple and easy to learn and use, easy to standardize, and can be accurately repeated
bisecting technique used to expose
periapical films
in bisecting technique:
film placed along lingual surface of tooth, where film contacts tooth-plane of film and long axis of tooth form an angle, imaginary bisector divides the angle in half or bisects it, and central ray of xray beam is directed perpendicular to the imaginary bisector
film size used with bisecting
2--positioned vertically for anterior and horizontally for posterior
incorrect horizontal angulation results in
correct vertical angulation has the tooth...
the same size as the film
excessive vertical angulation, tooth is shortened
insufficient vertical angulation, tooth is longer
bite-wing includes
crowns of maxillary and mandibular teeth, interproximal areas, and areas of crestal bone on the same film
four sizes of film
0,1,2,3...size 2 recommended
large areas of upper or lower jaw
size film used
occlusals used for:
localization of rooths, impacted teeth, foreign bodies, salivary stones; eval of size fo lesions, boundaries of maxillary sinus, and jaw fractures; exam of patients who cannot open their mouths; measurments of changes in size and shape of jaw
localization used for:
determining the buccal-lingual relationship of an object or to locate foreign bodies, impacted and unerupted teeth, retained roots, root positions, salivary stones, jaw fractures, broken needles and instruments, and filling matterials
2 Types of localization
buccal object rule
(Same=Lingual, Opposite=Buccal)
Right angle technique
dental radiographs should always be mounted when
immediately after processing
purpose of paralleling technique
aind in the diagnosis of diseases, lesions, and conditions that can not be identified clinically
Periapical (PA)
entire tooth and supporting structure, 2-3mm of bone around apex needed
bite-wing (BW)
interproximal surfaces of crowns of upper and lower and crestal bone, open contacts only-no overlap, vertical bitewing used on anteriors
occlusal film sizes
2 (kids) and 4 (adults)
intraoral film sizes
0-child, 1-narrow anterior, 2-adult, 3-preformed bitewing, 4-occlusal
routine bite-wings
2,4, or 6 film set, taken every 6 months, 1 year, or 2 years
FMX (Full mouth survey)
both BW and PA, taken once every 3-5 yrs, average adult has 18-20 films (14-16 Pa and 4-6 bw)
only use bisecting when
absolutely cannot get film parallel to the teeth
paralleling technique is also known as
long gone, right angle, extension cone
most common, 3 colors...(extension cone paralleling)
horizontal angulations in paralleling
centrals=0, molar=80-90, premolar=70-80. canine=45
bony growth on top of mouth
mandibular growths
edentulous spaces
no teeth
bisecting is also known as
the short cone technique
unguided film holders
snap-a-ray, stabe, bite tabs
vertical angulation of bisecting
central ray perpendicular to film and long axis of tooth
horizontal angulation of bisecting
central ray through contact areas of teeth
Before processing
after processing
film base
made of clear cellulose aceptate, transparent, blue tint
adhesive layer
covers both sides fo film base, serves to attach film enulsion to both sides of base
contains silver halide crystals, silver bromide, silver iodide
80-90% silver bromide, 1-10% iodide....suspended in gel
protective layer
thin coating that protects from scratches and damage
intraoral film
emulsion on both sides because requires less radiation
the larger the crystals...
the faster the film speed
speed a-f
slowest to fastest
D&F are only available
lead foil prevents
if film packet is placed backwards in mouth, the foil is visible on a developed radiograph
cephalometric film
shows bones of face and skull and the soft tissue palate
intensifying screen
used with external radiography on one side of the film
Calcium Tungstate
intensifying screen crystal, gives off blue light and must pair with blue-sensitive film
rare earth phosphors
intensifying screen-crystal, gives off green light and must pair with green-sensitive film
duplicating film
emulsion on one side, exposed to light it will turn light after developing