radiography test 1-history, BW, paralleling, bisecting, safety
state the basic rules of the BWX technique
*1. receptor placement*-premolar-need distal of canines and premolar--molar-need 3 mm beyond and 1st and 2nd molars *2. receptor position-*receptor is parallel to the teeth you want to capture *3. vertical angulation-*+10 *4. horizontal angulation-* PID is parallel to teeth and receptor--want open contacts *5. PID position-*PID must cover the entire receptor, if not will result in a cone cut
state the basic rules for taking periapicals for paralleling and bisecting technique?
*1. receptor placement-*want entire tooth we are projecting on center of receptor (ex. all of canine centered in middle and bone) *2. receptor position-*this is where paralleling and bisecting technique come in paralleling-receptor will be parallel to long axis of the tooth bisecting-place receptor close to tooth *3. vertical angulation-*paralleling-direct vertical angle so it is perpendicular to long axis of tooth -bisecting-direct vertical angle so it is bisecting (in between) the long axis of the tooth and receptor (vert. angulation is where elongation and forshortening happens) *4. horizontal angulation-*for both paralleling and bisecting-positioning tube head and direction of central ray is a horizontal or side-to-side plane *5. PID position-*PID needs to cover entire receptor
ALARA concept
*A*s *L*ow *A*s *R*easonably *A*chievable -states that all exposures must be kept to a minimum -want to prescribe least amount of films needed to reduce amount of exposure
advantages and disadvantages of paralleling tehnique
*advantages:* -easy -accurate -no distortion -can duplicate easily *disadvantages:* -difficult to place receptor -discomfort for pt
advantages and disadvantages of bisecting technique
*advantages:* -short object receptor distance (ORD) (film close to tooth) -no anatomical restrictions--can use on a shallow palate *disadvantages:* -image distortions -angulation problems-more guess work
lead apron and thyroid collar
*lead apron-*a flexible shield placed over the pt's chest and lap to protect the reproductive and blood-forming tissues from scatter radiation *thyroid collar-*flexible shield that is placed securely around pts' neck to protect the thyroid gland --is .25 mm of lead or lead equivalent materials --should be stored flat or hung-if folded can crack and then exposure would leak through
operator safety
*time-* -avoid retakes-take your time -never hold the tube-leave the room -never hold receptor for pt *shielding-* -be behind barrier (wall) 2.5-3 inches of drywall or 3/16 inches of steel or 1 mm of lead -exposure button permanently mounted on wall behind barrier *distance-* -need to be 6 feet away at 90-135 degrees from the head of the pt -in an open bay design, leave to take x-ray -make sure all other people are out of direct ray *radiation monitoring-* -area monitoring- a stick will be on wall to monitor radiation -personnel monitoring-everyone wears a badge for 1 month at waist level and then send in to see amount of radiation
maxillary vertical angle of topographic occlusal projection
+65 degrees
mandibular vertical angle topographic occlusal projection
-55 degrees
what are the requirements for a molar BW?
-MX and MN 1st and 2nd molars completely visible and 3 mm beyond -contact open between MX 1st and 2nd molars -minimum of 1 mm of alveolar crest visible -no cone cut
what are the requirements for a premolar periapical?
-all of premolars, distal of canine, and mesial of 1st molar are visible -contact areas are visible -1 mm of bone around apex -no cone cut -minor/no elongation or foreshortening -no overlapping of roots
what are the requirements for a premolar BW?
-all premolars and distals of both MX and MN canines visible -contact open between MN premolar and molar -minimum of 1 mm of alveolar crest visible -no cone cut
when are precautions taken to reduce radiation exposure?
-before exposure -during exposure -after exposure
what are the requirements for a central incisor periapcial?
-both central incisors completely visible -entire incisal edges visible -1 mm of bone around apex -no cone cut -minor/no elongation or foreshortening -no overlapping of roots
the discovery of x-rays/x-radiation
-discovered by Wilhelm Conrad Roentgen in 1895 -Roentgen experimented with a vacuum tube, an electrical current, and special screens covered with a material that glowed when exposed to radiation -Roentgen demonstrated that shadowed images could be permanently recorded on photographic plates by placing objects between the tube and the plate
the first x-ray tube
-discovered by William D. Coolidge in 1913 -a high-vacuum tube that contained a tungsten filament
the first prewrapped film
-discovered by the Eastman Kodak Company in 1913
what are the requirements for a molar periapical?
-entire 1st and 2nd molar visible and 3 mm and beyond -contact areas are visible -1 mm of bone around apex -no cone cut -minor/no elongation or foreshortening -no overlapping of roots
what are the requirements for a canine periapical?
-entire canine visible -entire incisal edge visible -1 mm of bone around apex -no cone cut -minor/no elongation or foreshortening -no overlapping of roots
what is the purpose of taking BWX?
-interproximal to detect caries -detect changes in bone -let's us know what kind of resortations/fillings are present --they are the most used x-ray recommended once a year to check for decay --is a 4 series, R&L molars and R&L premolars
intro of digital radiography
-introduced by General Electric in 1987 -uses an electronic sensor and a computer software -reduces pt exposure to radiation
intro of F-speed film
-introduced by General Electric in 2000 -is the fastest film -requires 60% of exposure time than D-speed -most recommended film to use
collimation/collimator
-is located between tube head and PID -used to restrict the size and shape of the primary beam and reduce pt exposure -restricts size of the beam at the pt's face to 2.75 inches -reduces volume of irradiated tissue -made of a lead plate
intro of D-speed film
-manufactured by F.G Fitzgerald (Kodak) in 1955 -D-speed film is the slowest intraoral film and requires the highest radiation to the pt -it creates images more sharp due to small crystal size
intro of E-speed film
-manufactured by General Electric in 1981 -requires less radiation than D-speed resulting in less exposure time to pt -has larger crystals than D-speed
the first dental x-ray machine
-manufactured by the Victor X-ray Corporation of Chicago in 1923 -they placed a miniature version of the x-ray tube inside the head of an x-ray machine and immersed in oil
topographic occlusal projection
-on MX used to examine palate and anterior teeth of the maxilla -on MN used to examine the anterior teeth of the mandible
the first kilovoltage machine
-produced by General Electric in 1957
total filtration
-state and federally regulated -equivalent of 1.5 mm aluminum for x-ray machines below 70 kVp (kilovoltage) and 2.5 mm aluminum for machines at 70 kVp
the first dental radiograph on a live pt in the U.S
-taken by C. Edmund Kells in 1896
the first dental radiograph
-taken by Otto Walkhoff in 1896 on himself
receptor holding decive
-takes the guess work out -eliminates need for pt to hold receptor in mouth -reduces # of retakes -stabilizes receptor -reduces possibility of receptor moving
maximum accumulated dose (MAD)
-the accumulated lifetime radiation dose--based on a workers age MAD=(current age-18)x0.05 Sv/year or MAD=(current age-18)x5 rems/year
maximum permissible dose (MPD)
-the maximum does equivalent that a body is permitted to receive within a specific period -radiographer worker: .05 SV or 5 rem or 20 mSv per year -general public: .001 or 0.1 rem or 1 mSv per year
how do dental radiographs benefit your pt?
-they detect and diseases, decay, and any trauma, resulting in better health -prevent or minimize problems -can tell if missing teeth or any extra teeth -can save time and money for pt
why is radiation safety important and why do we do it?
-to minimize radiation to pt and operator
why are there guidelines as to whom and when radiographs are taken on a pt?
-to minimize the amount of radiation exposure to pts and the radiographer -every pts mouth is different and may require more/less radiographs
filtration
-used in the x-ray tube head -the use of absorbing materials for removing the low-energy x-rays from the primary beam--want low-energy out --low-energy waves are long --high-energy waves are short
uses of dental radiographs
-used to check for decay between the teeth -show how well the upper and lower teeth line up -show bone loss when severe gum disease or a dental infection is present
positioning indicating device (PID)
-used to direct the x-ray beam -shape and length of PID effects how much exposure pt will have -can be round or rectangular--rectangular reduces exposure by 70% over round -longer PID has less divergence of the beam creating a smaller diameter of exposure to pt tissue
precautions taken before exposure
1. collimation 2.filtration 3. PID
precautions taken during exposure
1. lead apron and thyroid collar 2. digital imaging or fast film 3. receptor holding device 4. operator safety
what are the 3 types of intraoral radiopgraphic examinations?
1. periapical 2. interproximal (BWs) 3. occlusal
list and describe the step-by-step procedure for image mounting
1. place on paper towel over work surface in front of view box 2. turn on view box 3. label and date film mount 4. wash and dry hands 5. dot facing up 6. BW, anterior periapicals, posterior periapicals put in correct spot in film mount
precautions taken after exposure
1. proper film/sensor handling so you don't need to retake films (need to unbarrier PSP carefully and make sure hands are dry) 2. proper film processing/sensor retrieval (need to scan correctly)
what are the 5 steps in radiographic technique
1. receptor placement 2. receptor position 3. vertical angulation 4. horizontal angulation 5. PID position
what are the PID lengths?
8 and 16 inches
what should be on a periapical radiograph?
ALL of tooth/teeth and bone around it
know infection control!
CLEAN EVERYTHING
x-ray
a beam of energy that has the power to penetrate substances and record image shadows on receptor (photographic film or digital sensors)
pixel
a discrete unit of information, in digital images
angle
a figure formed by 2 lines diverging from a common point
radiation
a form of energy carried by waves or a stream of particles
x-radiation
a high-energy radiation produced by the collision of a beam of electrons with a metal target in an x-ray tube
dental radiograph
a photographic image produced on film by the passage of x-rays through teeth and related structures
full mouth series (FMS or FMX)
a series of intraoral dental images that show all tooth-bearing areas of the MX and MN jaw
identification dot
a small raised bump that appears on one corner of an intraoral film
cathode ray
a stream of high-speed electrons that originates from the cathode in an x-ray tube--resulted in a greenish fluorescence
occlusal projection
a type of intraoral examination used to inspect large areas of the maxilla or the mandible on one image
periapical examination
a type of intraoral imaging examination used to examine the entire tooth (crown and bone) and supporting bone
bisecting technique
aka bisecting angle technique or bisecting of the angle technique --is a method that can be used to expose periapical images
paralleling technique
aka extension cone paralleling technique (XCP), right-angle technique, and long-cone technique --used to expose periapical image receptors
added filtration
aluminum between collimator and tube head seal
right angle
an angle of 90 degrees formed by 2 lines perpendicular to each other
long axis of the tooth
an imaginary line that divides the tooth longitudinally into 2 equal halves
imaginary bisector
an imaginary plane that divides in half (or bisects) the angle formed by the receptor and the long axis of the tooth--it creates 2 equal angles and provides a common side for the 2 imaginary equal triangles
interproximal examination
an intraoral inspection used to examine the crowns of both MX and MN teeth on a single image
dental radiographer
any person who positions, exposes, and processes dental x-ray image receptors
interproximal
between two adjacent surfaces
alveolar bone
bone that surrounds and encases the roots of teeth
what is the condition that BWX radiographs primarily detect?
caries interproximally
crestal bone
coronal portion of alveolar bone found between teeth; aka the alveolar crest
receptor holder
device used to hold an intraoral receptor in the mouth; used to stabilize the receptors position during the exposure
what is the single most effective way to reduce radiation to a pt?
digital or fast film (F-speed)
target-receptor distance
distance between source of x-rays (PID) and receptor
image viewing
examination of dental radiographs
interpetation
explanation of what is viewed on a dental radiograph
inherent filtration
glass window of the x-ray tube, insulating oil, and the tube head seal
what type of angulation is determined by the side-to-side movement of the PID?
horizontal angulation
positive angulation
if the PID is positioned above the occlusal plane and the central ray is directed downward
negative angulation
if the PID is positioned below the occlusal plane and the central ray is directed upwards
elongation
images of teeth that appear too long *-results from too little vertical angulation* --also occurs if CR is directed perpendicular to the long axis of the tooth rather than to the imaginary bisector
foreshortening
images of the teeth that appear shortened *-results from too much vertical angulation* --also occurs if CR is directed perpendicular to the plane of the receptor rather than to the imaginary line
sensor
in digital imagining, a receptor that is used to capture an intraoral or extraoral image
bite-wing
includes crowns on MX and MN teeth, interproximal areas, and areas of crestal bone on the same image (aka interproximal technique)
what happens to the radiographic image when the object-receptor is increased?
increased imagine magnification
perpendicular
intersecting at or forming a right angle
indirect digital imaginig
method of obtaining a digital image from a sensor following exposure to x-rays by using a scanner to convert information into a digital form so that it can be viewed on a computer monitor
direct digital imagining
method of obtaining a digital image, in which an intraoral sensor is exposed to x-radiation to capture an image that can be viewed on a computer monitor
parallel
moving or lying in the same plane, always separated by the same distance and not intersecting
open contacts
on a dental image, opened contacts appear as thin as radiolucent lines between adjacent tooth surfaces
overlapped contacts
on a dental image, the area where the contact area of one tooth is superimposed over the contact area of an adjacent tooth
when the central ray is not directed through the contact ares, what is seen on the resulting radiograph?
overlap
what are the 2 techniques used for taking periapical radiogrpahs?
paralleling and bisecting
mount
place in an appropriate setting, as for display or study
receptor mount
placed in a film holder in anatomical order
receptor mounting
placement of radiographs in a supporting structure
what is the holder we use for BWX?
quick guide receptor
analog image
radiographic image produced by conventional film
receptor
something that responds to a stimulation; a recording medium
angulation
the alignment of the central x-ray beam in the horizontal and vertical planes
contact areas
the area where adjacent tooth surfaces contact/touch each other
horizontal bite-wing
the bite-wing receptor is placed in the mouth with the long portion of the receptor in a horizontal direction
vertical bite-wing
the bite-wing receptor is placed in the mouth with the long portion of the receptor in a vertical direction
central ray
the central portion of the primary beam of x-radiation (abbreviated CR)
object-receptor distance
the distance between the tooth and the receptor
fluorescence
the emission of a glowing light by certain substances when struck by light, cathode rays, or x-rays
what is the purpose of occlusal?
the examine large areas of the maxilla or mandible image
vertical angulation
the positioning of the PID in a vertical or up-and-down plane
horizontal angulation
the positioning of the central ray of the x-ray in a horizontal or side-to-side plane
dental radiography
the production of radiographs of the teeth and adjacent structures by the exposure of an image receptor to x-rays
what is the relationship between the long axis of the tooth and the receptor in the paralleling technique?
they are parallel
what is the relationship between the central ray and the imaginary bisector?
they are perpendicular
what is the relationship between the central ray and the receptor in the paralleling technique?
they are perpendicular
why do we use an increased target-receptor distance when using the paralleling technique?
to compensate for image magnification -ensures that only the most parallel rays will be directed at the tooth and receptor
what is the purpose of FMX
to detect caries and examine the entire tooth and surrounding bone -the techniques-paralleling and bisecting
bisect
to divide into 2 equal parts
why use an animage template when mounting?
to keep the images organized and easier to find
caries
tooth decay caused by microorganisms
how is the pt's head positioned before exposing radiographs?
up right and looking forward -teeth parallel to the floor
how is the pt's head positioned before exposing BW radiographs?
upright and facing forward -teeth parallel to the floor
buccal object rule
used to illustrate the orientation of structures portrayed in 2 images exposed at different angulation; used to determine the buccal-lingual relationship of an object
what type of angulation is determined by the up-and-down movement of the PID?
vertical angulation
when are vertical BWX indicated?
when examining the level of alveolar bone
when does a cone-cut result?
when the PID is misaligned and the central beam is not over the receptor
dentulous
with teeth; areas that exhibit teeth
edentulous
without teeth; areas where teeth are no longer present
