Radiology
1. When sending a full digital file, how should it be sent?
A) Open email attachment
B) Password-encrypted
C) Printed and mailed
D) Cloud link without encryption
Answer: B) Password-encrypted ✅
2. PID is considered:
A) Critical
B) Semi-critical
C) Non-critical
D) Disposable
Answer: C) Non-critical ✅
3. False statement:
A) Incorrect vertical angulation results in overlapped contact points
B) Incorrect horizontal angulation results in overlapped contact points
C) Incorrect vertical angulation does not affect contacts
D) Bitewings detect interproximal decay
Answer: A) Incorrect vertical angulation results in overlapped contact points ✅
4. Which tissue is highly radiosensitive?
A) Muscle
B) Skin
C) Bone
D) Nerve
Answer: B) Skin ✅
5. The 4 common errors in radiography include:
A) Two for bisecting, two for paralleling
B) Two for bitewing, two for pan
C) Two for vertical, two for horizontal
D) Two for PSP, two for digital sensors
Answer: A) Two for bisecting, two for paralleling ✅
6. Recommended for cleaning and disinfecting:
A) Surgical mask
B) Utility gloves
C) Safety glasses
D) Lab coat
Answer: B) Utility gloves ✅
7. ASC spectrum — safety glasses should:
A) Always be used
B) Never be used
C) Not required according to ASC spectrum
D) Only for PSP sensors
Answer: C) Not required according to ASC spectrum ✅
8. Cone beam computed tomography (CBCT) uses:
A) 2D imaging
B) 3D imaging technology
C) MRI technology
D) Ultrasound
Answer: B) 3D imaging technology ✅
9. Background radiation is:
A) Only in medical imaging
B) Only from natural sources
C) Always in our environment
D) Not measurable
Answer: C) Always in our environment ✅
10. Effective dose equivalent is used to:
A) Measure tooth density
B) Estimate radiation risk
C) Track equipment wear
D) Determine contrast
Answer: B) Estimate radiation risk ✅
11. Infection control is:
A) Only for immunocompromised patients
B) Only for staff
C) For everyone
D) Optional in certain clinics
Answer: C) For everyone ✅
12. Radiation injury sequence:
A) Period of injury → latent period → period of recovery
B) Latent period → period of injury → period of recovery
C) Period of recovery → latent period → period of injury
D) Latent period → period of recovery → period of injury
Answer: B) Latent period → period of injury → period of recovery ✅
13. On a panorex, if you see a shadow, you should:
A) Lower the chin
B) Put the tongue to the roof of your mouth
C) Ask the patient to swallow
D) Use a smaller FOV
Answer: B) Put the tongue to the roof of your mouth ✅
14. Sterilization vs Disinfection:
A) Sterilization reduces microbes, disinfectant destroys
B) Sterilization destroys, disinfectant reduces
C) Both destroy microbes completely
D) Disinfection sterilizes
Answer: B) Sterilization destroys, disinfectant reduces ✅
15. To break the chain of infection, do you need a digital sensor?
A) Yes
B) No
C) Only for children
D) Only for adults
Answer: B) No ✅
16. Receptor holders are classified as:
A) Critical
B) Semi-critical
C) Non-critical
D) Disposable
Answer: B) Semi-critical ✅
17. PSP plates may be affected by:
A) Prolonged light exposure
B) Cold temperature
C) Water contact
D) Short x-ray exposure
Answer: A) Prolonged light exposure ✅
18. Once an image receptor is removed, you should:
A) Throw it away
B) Wipe it with paper towel or gauze
C) Leave it on the counter
D) Rinse with water
Answer: B) Wipe it with paper towel or gauze ✅
19. Trabecular patterns can appear:
A) Only radiopaque
B) Only radiolucent
C) Either radiopaque or radiolucent
D) Invisible
Answer: C) Either radiopaque or radiolucent ✅
20. XDP ring color for tooth #19 is:
A) Red
B) Blue
C) Yellow
D) Green
Answer: C) Yellow ✅
21. Tongue against the roof of the mouth during a pan reduces:
A) Nasopharyngeal airspace
B) Palatoglossal airspace
C) Oropharyngeal airspace
D) Mental fossa airspace
Answer: B) Palatoglossal airspace ✅
22. DHCP stands for:
A) Dental Healthcare Personnel
B) Dental Health Care Procedure
C) Diagnostic Health Care Provider
D) Digital Health Care Practitioner
Answer: A) Dental Healthcare Personnel ✅
23. Advanced decay radiographically appears as:
A) Small pinpoint radiolucency
B) Double triangle halfway through dentin
C) Fully radiopaque lesion
D) Crescent shape at enamel
Answer: B) Double triangle halfway through dentin ✅
24. Can bitewings locate abscesses?
A) Yes
B) No
C) Only in children
D) Only in posterior teeth
Answer: B) No ✅
25. Radiolucent images appear dark due to:
A) High density
B) Less density
C) Overexposure
D) Filter use
Answer: B) Less density ✅
26. Correct head positioning for a pan:
A) Midsagittal plane parallel to floor, Frankfort plane perpendicular
B) Midsagittal plane perpendicular, Frankfort plane parallel
C) Both parallel
D) Both perpendicular
Answer: B) Midsagittal plane perpendicular, Frankfort plane parallel ✅
27. Tube head classification — transfer, touch, or splash:
A) Splash
B) Transfer
C) Touch
D) All of the above
Answer: B) Transfer ✅
28. Cone cutting occurs due to:
A) Improper sensor exposure time
B) Failure to center the central ray
C) Patient movement
D) Using PSP instead of digital
Answer: B) Failure to center the central ray ✅
29. Cervical vertebrae may appear on a pan because:
A) Patient is standing upright
B) Patient is not standing straight
C) Exposure time too long
D) Chin is tipped up
Answer: B) Patient is not standing straight ✅
30. Bitewings detect decay primarily on:
A) Occlusal surfaces
B) Interproximal surfaces (mesial or distal)
C) Root surfaces
D) Entire tooth structure
Answer: B) Interproximal surfaces (mesial or distal) ✅
31. Composite resin on X-rays is:
A) Most radiopaque
B) Least radiopaque
C) Always radiolucent
D) Invisible
Answer: B) Least radiopaque ✅
32. Which teeth can initiate a gag reflex?
A) Mandibular incisors
B) Maxillary molars
C) Mandibular molars
D) Maxillary canines
Answer: B) Maxillary molars ✅
33. Cervical vertebrae may appear in a pan due to:
A) Patient tilting chin up
B) Patient not standing up straight
C) Low kVp setting
D) Use of bitewing sensor
Answer: B) Patient not standing up straight ✅
34. For a gag reflex, do you tell the patient to think about gagging?
A) Yes
B) No
C) Only for children
D) Only for adults
Answer: B) No ✅
35. Who prescribes radiographs?
A) Dental assistant
B) Patient
C) Dentist
D) Hygienist
Answer: C) Dentist ✅
36. SI units — which is NOT part of SI?
A) Sievert
B) Gray
C) Rem
D) Coulomb
Answer: C) Rem ✅
37. Human tissue is composed mostly of:
A) Protein
B) Lipids
C) Water (H2O)
D) Calcium
Answer: C) Water (H2O) ✅
38. Spine appears on X-ray as:
A) Radiolucent
B) Radiopaque
C) Invisible
D) Mixed
Answer: B) Radiopaque ✅
39. Voxels in CBCT capture:
A) Only width and height
B) Only length and width
C) 3D dimensions
D) Only grayscale
Answer: C) 3D dimensions ✅
40. A larger voxel setting in CBCT:
A) Increases spatial resolution
B) Decreases spatial resolution and decreases electronic noise
C) Increases image noise
D) Has no effect
Answer: B) Decreases spatial resolution and decreases electronic noise ✅
41. SDS sheet — section 4 includes:
A) Composition
B) First aid measures
C) Disposal
D) Manufacturer info
Answer: B) First aid measures ✅
42. The three planes for CBCT imaging are:
A) Axial, coronal, sagittal
B) Transverse, diagonal, vertical
C) Horizontal, vertical, lateral
D) Sagittal, oblique, diagonal
Answer: A) Axial, coronal, sagittal ✅
43. Lateral cephalometric radiographs are typically performed in:
A) Hygiene office
B) Ortho office
C) Pediatric office
D) Endodontic office
Answer: B) Ortho office ✅
44. After a radiographic procedure, you should use:
A) Surgical mask
B) Utility gloves to clean surfaces
C) Only disinfectant wipes
D) Nothing if patient is gone
Answer: B) Utility gloves to clean surfaces ✅
45. Lamina dura outlines:
A) Crown of tooth
B) Root of tooth
C) Pulp chamber
D) Periodontal ligament
Answer: B) Root of tooth ✅
46. CDC recommends:
A) No barriers on X-ray button
B) Barrier over X-ray button
C) Wiping only with alcohol
D) No cleaning required
Answer: B) Barrier over X-ray button ✅
47. Frankfort horizontal plane should be:
A) Parallel to the ground
B) Perpendicular to the ground
C) Tilted 10° upward
D) Tilted 10° downward
Answer: A) Parallel to the ground ✅
48. Facial landmark too low — exaggerated smile line — indicates:
A) Chin tipped too high
B) Chin tipped too low
C) Tongue not against palate
D) Head twisted
Answer: B) Chin tipped too low ✅
49. Positioning too far forward in the focal trough causes:
A) Teeth to appear blurred and diminished
B) Teeth to appear elongated
C) Teeth to appear superimposed
D) Tongue shadows
Answer: A) Teeth to appear blurred and diminished ✅
50. Facial bones that can appear in a panoramic X-ray:
A) Zygoma
B) Maxillary sinus only
C) Mandibular condyle only
D) Orbit only
Answer: A) Zygoma ✅
51. Contrast in radiographs is controlled by:
A) mA
B) Exposure time
C) kVp
D) Focal spot size
Answer: C) kVp ✅
52. Smile error on pan occurs when:
A) Chin is too far up
B) Chin is too far down
C) Tongue not positioned
D) Patient swallows
Answer: B) Chin is too far down ✅
53. Direct supervision means:
A) Doctor is in the office
B) Doctor is on phone
C) Doctor is offsite
D) Assistant can decide independently
Answer: A) Doctor is in the office ✅
54. Two pictograms indicating hazards include:
A) Flammable and toxic
B) Carcinogenic and eye irritant
C) Explosive and corrosive
D) Radioactive and oxidizer
Answer: B) Carcinogenic and eye irritant ✅
55. Short-scale contrast is:
A) Gray with many shades
B) Black and white with few shades of gray
C) Always low contrast
D) High kVp only
Answer: B) Black and white with few shades of gray ✅
56. Excessive vertical angulation requires:
A) Decrease angulation
B) Increase angulation
C) No adjustment
D) Change sensor
Answer: A) Decrease angulation ✅
57. Inadequate vertical angulation requires:
A) Decrease angulation
B) Increase angulation
C) No adjustment
D) Switch to bitewing
Answer: B) Increase angulation ✅
58. Common area for dangerous cysts:
A) Maxillary lateral
B) First premolar
C) Third molar
D) Canine region
Answer: C) Third molar ✅
59. Leaded glass housing in tube head prevents:
A) Overexposure to operator
B) X-rays from escaping tube head
C) Sensor damage
D) Patient discomfort
Answer: B) X-rays from escaping tube head ✅
60. Median palatine suture is seen on:
A) Mandibular anterior PA
B) Maxillary anterior PA
C) Maxillary posterior PA
D) Panoramic only
Answer: B) Maxillary anterior PA ✅
61. Exceptions about CBCT artifacts include:
A) Increasing FOV
B) Patient movement
C) Metallic restorations
D) Scatter radiation
Answer: A) Increasing FOV ✅
62. Inverted Y on a radiograph indicates:
A) Intersection of nasal wall and maxillary sinus
B) Mandibular canal crossing
C) Zygomatic arch
D) Lamina dura
Answer: A) Intersection of nasal wall and maxillary sinus ✅
63. Which technique is not ideal for children?
A) Paralleling
B) Bisecting
C) Bitewing
D) Panoramic
Answer: A) Paralleling ✅
64. Conditions required for X-rays to be produced include:
A) Electrons, speed, and target
B) Air-filled glass tube, electrons, speed
C) Only electrons and target
D) Only speed and target
Answer: A) Electrons, speed, and target ✅
65. Panoramic X-ray — patient can:
A) Only stand
B) Only sit
C) Stand or sit, must remain still
D) Move slightly during exposure
Answer: C) Stand or sit, must remain still ✅
66. Absorbed dose measures:
A) Radiation reaching the sensor
B) Energy deposited in teeth or soft tissue
C) Kilovoltage of the tube
D) Time of exposure
Answer: B) Energy deposited in teeth or soft tissue ✅
67. Stainless steel crown appears on X-ray as:
A) Radiolucent
B) See-through appearance
C) Radiopaque
D) Mixed
Answer: B) See-through appearance ✅
68. Abscess on tooth #25 — which image is preferred?
A) Bitewing
B) PA
C) Panoramic
D) Occlusal
Answer: B) PA ✅
69. To increase contrast while maintaining density, you should:
A) Increase kVp
B) Decrease kVp and increase mA
C) Decrease mA only
D) Increase exposure time
Answer: B) Decrease kVp and increase mA ✅
70. PSP plates produce images:
A) Almost instantaneously
B) Not almost instantaneously
C) Only after development
D) Only digitally
Answer: B) Not almost instantaneously ✅
71. Absence of teeth is called:
A) Anodontia
B) Supernumerary
C) Hypodontia
D) Oligodontia
Answer: A) Anodontia ✅
72. ALARA principle is:
A) Optional for dental staff
B) Mandatory for patients
C) Ethical principle to minimize radiation exposure
D) Used only for children
Answer: C) Ethical principle to minimize radiation exposure ✅
73. Preferred method for sharing digital images:
A) USB
B) Cloud
C) Printed film
D) Email without encryption
Answer: B) Cloud ✅
74. Do you need a dark room for digital images?
A) Yes
B) No
C) Only for PSP
D) Only for film
Answer: B) No ✅
75. Lateral cephalometric has:
A) Most radiation
B) Least radiation on extraoral film
C) Moderate radiation
D) Radiation depends on age
Answer: B) Least radiation on extraoral film ✅
76. OSHA stands for:
A) Occupational Safety and Health Administration
B) Organization for Safety and Hygiene in America
C) Occupational Standards for Health Assistants
D) Organization of Safety and Hazard Assessment
Answer: A) Occupational Safety and Health Administration ✅
77. Increasing mA:
A) Lightens radiograph
B) Darkens radiograph
C) Reduces exposure time
D) Reduces contrast
Answer: B) Darkens radiograph ✅
78. Informed consent means:
A) Patient can do anything they want
B) Patient understands risks and consents to procedure
C) Doctor decides without explanation
D) Only verbal consent is needed
Answer: B) Patient understands risks and consents to procedure ✅
79. Incisive foramen is recorded on:
A) Mandibular anterior
B) Maxillary anterior between teeth #8 & 9
C) Maxillary posterior
D) Mandibular posterior
Answer: B) Maxillary anterior between teeth #8 & 9 ✅
80. Collimator function:
A) Increases beam size
B) Reduces size of the beam
C) Adjusts exposure time
D) Controls contrast
Answer: B) Reduces size of the beam ✅
81. True about 3D tomography (CBCT):
A) Produces 2D images
B) Produces 3D images
C) Produces only bitewing images
D) Cannot visualize bone
Answer: B) Produces 3D images ✅
82. The “filter” in radiography:
A) Protects operator
B) Removes low-energy photons
C) Increases contrast
D) Reduces patient comfort
Answer: B) Removes low-energy photons ✅
83. CBCT should not be used for:
A) Proximal caries detection
B) Implant planning
C) TMJ evaluation
D) Airway analysis
Answer: A) Proximal caries detection ✅
84. Image receptor with widest dynamic range:
A) PSP
B) Digital sensor
C) Film
D) Panoramic sensor
Answer: A) PSP ✅
85. Who provides the SDS sheet?
A) Clinic
B) Manufacturer
C) Regulatory agency
D) Dental assistant
Answer: B) Manufacturer ✅
86. To help prevent gag reflex:
A) Salt on tongue
B) Water rinse only
C) Breathing exercises
D) Tongue depressor
Answer: A) Salt on tongue ✅
87. Lead aprons are classified as:
A) Critical
B) Semi-critical
C) Non-critical
D) Disposable
Answer: C) Non-critical ✅
88. The pulp appears on X-ray as:
A) Radiopaque
B) Radiolucent
C) Mixed
D) Invisible
Answer: B) Radiolucent ✅
89. Amalgam tattoo on a radiograph is:
A) Radiolucent
B) Radiopaque
C) Invisible
D) Mixed
Answer: B) Radiopaque ✅
90. Supernumerary teeth are best seen on:
A) Bitewing
B) Panoramic
C) PA
D) Occlusal
Answer: B) Panoramic ✅
91. Genial tubercles are located:
A) Maxillary anterior
B) Mandibular anterior
C) Maxillary posterior
D) Mandibular posterior
Answer: B) Mandibular anterior ✅
92. Infraorbital foramen is seen on:
A) Maxillary posterior
B) Mandibular posterior
C) Maxillary anterior
D) Mandibular anterior
Answer: C) Maxillary anterior ✅
93. Do not use occlusal #4 for:
A) Bitewings
B) Periodontal evaluation
C) PA images
D) Pediatric imaging
Answer: B) Periodontal evaluation ✅
94. Somatic cells can repair; genetic cells:
A) Can repair equally
B) Cannot repair
C) Repair faster
D) Are not affected by radiation
Answer: B) Cannot repair ✅
95. Coronoid process is likely recorded on:
A) Maxillary anterior
B) Maxillary posterior — triangular shape
C) Mandibular anterior
D) Mandibular posterior
Answer: B) Maxillary posterior — triangular shape ✅
96. Rectangular PID reduces radiation by:
A) 30%
B) 50%
C) 70%
D) 90%
Answer: C) 70% ✅
97. Acute radiation syndrome (ARS) is considered:
A) Short-term exposure
B) Long-term exposure
C) Genetic mutation only
D) Chronic exposure
Answer: A) Short-term exposure ✅
98. Most radiosensitive blood cells:
A) Red blood cells
B) Platelets
C) White blood cells
D) Plasma cells
Answer: C) White blood cells ✅
99. Professional code of ethics governs:
A) Equipment usage
B) Conduct
C) Billing
D) Patient education
Answer: B) Conduct ✅
100. Mental fossa appears on X-ray as:
A) Radiopaque elevated area
B) Radiolucent depressed area of bone
C) Invisible
D) Mixed
Answer: B) Radiolucent depressed area of bone ✅