DENTAL RADIOLOGY 2026/2027 QUESTIONS AND
SOLUTIONS RATED A+
✔✔herringbone - ✔✔film placed backwards (concave instead of convex)
✔✔overlapping - ✔✔crowns appear to be on top of each other
✔✔cone cut - ✔✔PID not centered over film
✔✔elongation - ✔✔insufficient vertical angulation
teeth appear longer than actual size
✔✔foreshortening - ✔✔vertical angulation too high
teeth appear shorter than actual size
✔✔fog - ✔✔hazy appearance on film
many causes
✔✔black film - ✔✔can be caused by overdeveloping, developer too hot, or exposure to
white light after x-ray exposure
✔✔exhausted chemicals - ✔✔cause film to be too light, fogged, or tinted brown
exhausted fixer pictured
✔✔developer too cool - ✔✔film too light
✔✔developer too warm - ✔✔film too dark
✔✔reticulation - ✔✔crackled appearance
caused by extreme difference in solution temperatures
✔✔films stuck together - ✔✔
✔✔interproximal film - ✔✔bitewing
shows crowns of both upper and lower teeth on same film
used to diagnose interproximal caries
sizes 0, 1, 2, or 3
✔✔radiolucent - ✔✔portion of film that is dark due to lack of structural density
substance permits passage of x-rays with little to no resistance
✔✔radiopaque - ✔✔portion of film that is light due to higher structural density
substance resists passage of radiation
, ✔✔secondary radiation - ✔✔given off my any matter irradiated with x-rays
created when the primary beam interacts with matter and gives off energy
✔✔soft x-rays - ✔✔rays of low energy and long wavelengths
have little penetrating power
removed from beam by filtration
✔✔Roentgen (R) - ✔✔unit of exposure to radiation measured in air
replaced by coulombs/kg
✔✔Sievert (Sv) - ✔✔measures the dose equivalent
✔✔periapical film - ✔✔shows the entire tooth or teeth and surrounding tissues
✔✔PPE (personal protective equipment) - ✔✔personal barriers worn to prevent
contamination
gloves, mask, eyewear, and gowns
✔✔occlusal plane - ✔✔plane between maxillary and mandibular teeth
forms a slight upward curve - Curve of Spee
✔✔TLD - ✔✔monitoring device containing crystalline compounds that store energy
when struck by x-rays
determine amount of radiation exposure
✔✔RAD - ✔✔unit of absorbed dose equal to 0.01 joule/kg of tissue
approximately equal to R
replaced by Gray
✔✔Gray (Gy) - ✔✔measures absorbed dose
1 Gy = 100 rad
✔✔REM - ✔✔measures the dose equivalent
compares biological effects of various types of radiation
replaced by Sievert (Sv)
✔✔Iowa Department of Public Health - ✔✔state radiation control agency
inspects facilities
✔✔Iowa Dental Board - ✔✔ensures dental assistants meet minimum training standards
issues qualification in dental radiography
✔✔conditions for an assistant to take radiographs - ✔✔assistant is qualified in dental
radiography or is on trainee status
SOLUTIONS RATED A+
✔✔herringbone - ✔✔film placed backwards (concave instead of convex)
✔✔overlapping - ✔✔crowns appear to be on top of each other
✔✔cone cut - ✔✔PID not centered over film
✔✔elongation - ✔✔insufficient vertical angulation
teeth appear longer than actual size
✔✔foreshortening - ✔✔vertical angulation too high
teeth appear shorter than actual size
✔✔fog - ✔✔hazy appearance on film
many causes
✔✔black film - ✔✔can be caused by overdeveloping, developer too hot, or exposure to
white light after x-ray exposure
✔✔exhausted chemicals - ✔✔cause film to be too light, fogged, or tinted brown
exhausted fixer pictured
✔✔developer too cool - ✔✔film too light
✔✔developer too warm - ✔✔film too dark
✔✔reticulation - ✔✔crackled appearance
caused by extreme difference in solution temperatures
✔✔films stuck together - ✔✔
✔✔interproximal film - ✔✔bitewing
shows crowns of both upper and lower teeth on same film
used to diagnose interproximal caries
sizes 0, 1, 2, or 3
✔✔radiolucent - ✔✔portion of film that is dark due to lack of structural density
substance permits passage of x-rays with little to no resistance
✔✔radiopaque - ✔✔portion of film that is light due to higher structural density
substance resists passage of radiation
, ✔✔secondary radiation - ✔✔given off my any matter irradiated with x-rays
created when the primary beam interacts with matter and gives off energy
✔✔soft x-rays - ✔✔rays of low energy and long wavelengths
have little penetrating power
removed from beam by filtration
✔✔Roentgen (R) - ✔✔unit of exposure to radiation measured in air
replaced by coulombs/kg
✔✔Sievert (Sv) - ✔✔measures the dose equivalent
✔✔periapical film - ✔✔shows the entire tooth or teeth and surrounding tissues
✔✔PPE (personal protective equipment) - ✔✔personal barriers worn to prevent
contamination
gloves, mask, eyewear, and gowns
✔✔occlusal plane - ✔✔plane between maxillary and mandibular teeth
forms a slight upward curve - Curve of Spee
✔✔TLD - ✔✔monitoring device containing crystalline compounds that store energy
when struck by x-rays
determine amount of radiation exposure
✔✔RAD - ✔✔unit of absorbed dose equal to 0.01 joule/kg of tissue
approximately equal to R
replaced by Gray
✔✔Gray (Gy) - ✔✔measures absorbed dose
1 Gy = 100 rad
✔✔REM - ✔✔measures the dose equivalent
compares biological effects of various types of radiation
replaced by Sievert (Sv)
✔✔Iowa Department of Public Health - ✔✔state radiation control agency
inspects facilities
✔✔Iowa Dental Board - ✔✔ensures dental assistants meet minimum training standards
issues qualification in dental radiography
✔✔conditions for an assistant to take radiographs - ✔✔assistant is qualified in dental
radiography or is on trainee status
