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final exam rad
all quizzes from rad
Question | Answer |
---|---|
After viewing an image made of a maxillary pre-molar periapical, you observe that the distal half of the canine is not visible. To correct the error on the retake, you would: | reposition the sensor more anteriorly |
What does a herringbone pattern on an exposed then processed film indicate? | the film packet was placed backwards in the oral cavity |
What indicates that the radiograph was overexposed? | Dark image |
Overexposing would result in a processed film being too light | False |
Accidental white light exposure would result in a radiograph that is blank (clear) | True |
Static electricity on conventional radiographs appear as ? | thin black lines |
One would correct foreshortening by: | decreasing the vertical angulation |
You process a film manually. The developing solution was very hot; and the fixing solution was very cold. The result of this processed film will be a: | reticulated image |
You acquire a mandibular central incisor periapical image and there is a very large incisal margin. This problem was caused by: | the patient did not close fully onto the receptor holder |
Using a F-E speed film will contribute to film fogging | False |
You forget to remove the patient's mandibular partial denture and then make bitewing images. This will result in a: | superimposed image |
Possible causes for light films include: | underexposure, underdevelopment, low temperature processing |
When overlapped contacts appear on the image, the cause is: | incorrect horizontal angulation |
A manually processed film which has not been sufficiently washed will eventually appear: | brown |
Insufficient vertical angulation results in: | elongation |
Varying the time and temperature during manual film processing has no effect on the processed image | False |
What is the correct manual processing sequence? | develop, rinse, fix, wash, dry |
The amount of time that unwrapped intraoral films can be exposed to safelighting without affecting image quality is approximately: | 2-3 minutes |
The type of safelight which is safe for all films (including extraoral) is the: | GBX 2 |
Using an f-speed film rather than an e-speed film to produce a radiograph results in: | less patient exposure |
What is the hardening agent? | Potassium Alum |
What is the restrainer? | Potassium Bromide |
What is the preservative? | Sodium Sulfite |
What is the clearing agent? | Hypothiosulfate |
What is one of the reducing agents used in the developer? | hydropuinone |
What softens/swells emulsion in developer? | sodium bicarbonate |
What is the ideal temperature when films are processed manually? | 68 degrees |
selective reduction is defined as that process whereby the fixer acts only upon the exposed silver halide crystals of the film emulsion to reduce them to black metallic silver | false |
automatic processors produce processed films faster than manual development because they utilize highly saturated solutions which operate at higher temperatures | true |
rapid processing solutions provide rapid information but at the expense of the quality of the film. | true |
you perform the coin test for safelighting and find that an outline of the coin is visible on the processed film. The safelighting is therefore is not safe. | true |
What are the two essential actions of the fixer solution? | -fixes and hardens the image, - takes away the unexposed silver bromide crystals |
What is the purpose of the black paper in the film packet? | helps keep film from being exposed |
What is the purpose of the lead foil in the film packet? | stops any back scatter radiation to go any further |
The image on the exposed dental film which is not made available until processing is termed the ______ image. | latent |
what is the portion of the cell that is damaged when a genetic mutation results? | DNA |
true or false? Cumulative effects of x-radiation exposure lead to health problems | true |
true or false? all radiation injuries become evident immediately | false |
true or false? x-radiation only injures somatic cells | false |
true or false? the latent period is long when a single large dose of radiation is received | false |
what is the first clinical sign of excessive exposure to radiation? | erythema |
what is the most dangerous time for a fetus to be exposed to ionizing radiation? | 1st trimester |
Why is a child's cell more susceptible to damage from x-radiation than adult cells? | more rapid cell reproduction |
Identify the cells form those listed below which are more sensitive to x-radiation; nerve cells, muscle cells, red blood cells, cardiac cells | red blood cells |
what is the maximum permissible dose (MPD) than an occupationally exposed person can receive in a year? | .05 SV/year (5.0 rem/year) |
which of the following cells are most sensitive to radiation? muscle, nerve, sperm, epithelium | sperm |
How far away should the operator stand when making a radiograph? | at least 6 feet away from the x-ray tube and patient |
true or false? The amount of radiation a person receives is cumulative in the entire body | true |
what is the purpose of the radiation badge? | to monitor the radiation exposure the radiographer receives |
radiation effects that occur in the exposed person, not in the reproductive cells are termed: | somatic effects |
this theory suggests that x-ray energy is absorbed within the cell and causes the formation of toxins which in turn damage cells | indirect theory of intercellular damage |
this standard international term places exposure effects on a common scale and is used to compare the biologic effects of various radiation types on body tissues | sievert |
cell sensitivity to radiation exposure depends upon all of the following except: type of cell, individual response, dose rate, cell differentiation, ethnicity | ethnicity |
true or false? a measure of ionization produced in air is referred to as the Roentgen or Coulomb per kg | true |
true or false? effects from radiation exposure that occur years, decades and even generations later are referred to as long term effects | true |
the most radiosensitive cell of the body is the reproductive cell of sperm and ova | false |
the thyroid gland, bone marrow, skin and eyes are considered critical organs of concern in dentistry | true |
Define the Latent Period | The period of time between exposure to radiation and first observable clinical affects |
compute your maximum accumulated dose (MAD) | (20-18) x 5 = 10 rems |
what does the acronym ALARA stand for? | As Low As Reasonably Achievable |
What is ALARA important? | dont want the patient to receive any unnecessary x-radiation if you can get what you need at a smaller dose of x-radiation |
x-ray machines operating at kvp's higher than 70 need what? | 2.5 mm of aluminum filtration |
what is the sum of the inherent and the added filtration? | total filtration |
what is density? | the degree of overall film blackness |
what is collimation | the restriction of the size of the x-ray beam |
what is contrast? | the differences in degrees of blackness between adjacent areas on the radiograph |
what is sharpness? | distinct outline and specified details of the included structures (also referred to as detail, definition, or resolution) |
60 impulses = ? | 1 second |
what is the kilovoltage peak rule? | when kilovoltage peak is increased by a factor of 15, the exposure time should be decreased by one-half |
what is the inverse square law? | the intensity of radiation is inversely proportional to the square of the target to film/receptor distance |
to produce a larger quantity of electrons for the production of x-rays, the radiographer would increase what? | mA (milliamperage) |
what is the term that describes the electrical pressure or force that drives the electric current through the circuit of the x-ray machine? | voltage |
the process of heating the cathode wire filament until red hot and electrons are boiled off is termed? | thermionic emission |
what metal is used for the target in the x-ray tube? | tungsten |
what percent of the kinetic energy inside the x-ray tube is converted into x-rays? | 1% |
What controls the penetrating power of the x-ray beam? | milliamperage |
while pressing the exposure button the radiographer will hear an audible beep indicating that? | x-rays are being produced |
the step down transformer is located where? | in the cathode circuit |
true or false? the focal spot improves definition by concentrating electrons into a very small area | true |
true or false? the actual focal spot is rectangular and serves to allow for greater dissipation of the heat generated | true |
true or false? the metal used for the target within the x-ray tube in modern x-ray tubes satisfies all of the properties of an ideal target material | false |
true or false? x-rays are produced in a series of bursts or pulses rather than as a steady stream | true |
true or false? milliiamperage determines the speed by which the electrons travel to the target. | false |
true or false? the dental x-ray tube is self-rectified | true |
true or false? the effective focal spot serves to enhance image sharpness | true |
true or false? a step down transformer has more wire coils in the secondary coil than in the primary coil | false |
the tungsten target is angled in the copper stem at a ------ degree angle. | 20 |
radiation is defined as? | a form of energy carried by waves |
true or false? many dental diseases are typically discovered only through the use of dental radiographs | true |
Who is Dr. Raper? | he is responsible for introducing radiology into the dental school curriculum |
the nucleus of an atom contains? | protons and neutrons |
true or false? an oral examination with dental radiographs limits the practitioner to what is seen clinically. | false |
true or false? many dental diseases are typically discovered only through the use of dental radiographs | true |
true or false? all dental diseases and conditions produce clinical signs and symtoms | false |
true or false? dental radiographs are not necessary component of comprehensive patient care | false |
true or false? the K shell is closest to the nucleus and has the highest energy level | true |
true or false? protons travel around the nucleus in well-defined shells | false |
true or false? an atom contains an infinite number of shells | false |
true or false? the energy level within each shell is the same | false |
what are the 5 rules of shadow casting? | (refer to paper for answer) |
true or false? x-rays were discovered by Wilhelm Roentgen | true |
true or false? pointed "cones" produce scatter radiation and are no longer recommended | true |
what is external root resorption? | the destruction of root structure from an outside source (i.e. orthodontics) |
what is internal root resorption? | is traumatically induced, and develops from an inflammatory response within the pulp |
what is physiological root resorption? | NORMAL resorption of deciduous teeth as a result of the incoming successor |
what is secondary dentin? | a normal aging response, can also occur as a dense mechanism to caries, etc. teeth are more yellow due to this |
what are pulp stones? | round or oval opacities within the pulp, composed of dentin or calcified salts, very common, and usually have no significance |
what is condensing osteitis? | irregular radiopacities within the bone, usually a reaction of bone to a low grade inflammation |
what is hypercementosis? | excess calcification of the root cementum of a tooth, results in a "clubbing" of root end |
what is ankylosis? | a tooth that is fused to surrounding bone, preventing exfoliation |
what is abrasion? | a physical wearing away of root structure leading to less density in affected area |
what is abfraction? | a wearing away of root structure from unusual stress on neck of tooth |
what is attrition? | occlusal wear on teeth seen clinically observed radiographically |
what is erosion? | loss of tooth structure from chemical action |
what is fusion? | two teeth joined early in development to form a single large tooth |
what is gemination? | a single tooth germ splits to form a single large crown (same tooth count) |
what is concrescence? | two well formed teeth are joined by their cementum layers |
what is dens in dente? | a tooth within a tooth |
what is taurodontism? | teeth with large bodies and pulp chambers with very little root formation |
what is macrodontia? | a very large tooth for the dentition |
what is microdontia | a very small tooth for the dentition |
what is amelogenesis imperfecta | enamel fails to achieve its proper thickness |
what is dentinogenesis imperfecta? | a developmental disturbance of dentin formation |
what is supernumerary teeth? | extra teeth |
what are malposed teeth? | due to the lack of space or obstruction |
what are the most common impacted teeth? | maxillary and mandibular 3rd molars |
how do you identify impaction? | by orientation |
what is tori? | bony projections encountered on palate or lingual surface of the mandible |
how does tori appear on radiographs? | radiopaque projections superimposed over apical areas of maxillary teeth for palatal tori; superimposed over the roots of mandibular teeth for mandibular tori |
what is enamel pearl? | small globule of enamel occurring in the roots of molars, especially at the furcation of the roots |
what are salivary stones? | appear within glands, spherical shaped opacities with irregular borders |
what is dilaceration? | deformed teeth caused by injury in development, especially mechanical trauma |
what are fractures? | discontinuity in outline of tooth |