Dental Radiography Techniques Practice Questions
20 free Dental Radiography Techniques practice questions for the CDA. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which radiographic technique is considered the most accurate for periapical imaging?
- A Bisecting angle technique
- B Paralleling technique
- C Occlusal technique
- D Topographical technique
Correct answer: Paralleling technique
The paralleling technique produces images with minimal distortion. It is preferred due to its accurate representation of tooth anatomy.
Which radiograph is best suited for evaluating interproximal caries?
- A Periapical
- B Panoramic
- C Bitewing
- D Occlusal
Correct answer: Bitewing
Bitewing radiographs clearly show the crowns of posterior teeth and the interproximal spaces. They are the standard for detecting caries between teeth.
In the bisecting angle technique, the central ray is directed perpendicular to which surface?
- A The surface of the receptor
- B The long axis of the tooth
- C The tooth-and-receptor bisector
- D The occlusal plane of the arch
Correct answer: The tooth-and-receptor bisector
The bisecting technique follows the rule of isometry. The beam must be perpendicular to the bisector to minimize distortion.
What is the recommended vertical angulation for bitewing radiographs?
- A +5 degrees
- B +10 degrees
- C 0 degrees
- D -10 degrees
Correct answer: +10 degrees
+10 degrees helps project the maxillary and mandibular crowns evenly. Incorrect angulation can distort interproximal spaces.
Which radiographic series is used to detect early changes in bone levels?
- A Periapical series
- B Bitewing series
- C Occlusal series
- D Panoramic series
Correct answer: Bitewing series
Bitewings show crestal bone height clearly. They are essential for diagnosing early periodontal disease.
Which technique reduces magnification and improves image sharpness?
- A Short PID with bisecting technique
- B Long PID with paralleling technique
- C Occlusal topographical technique
- D Short PID with occlusal technique
Correct answer: Long PID with paralleling technique
The paralleling technique with a long PID reduces beam divergence. This results in sharper, more accurate images.
What positioning error results in overlapping contact areas on a bitewing radiograph?
- A Incorrect vertical angulation
- B Incorrect horizontal angulation
- C Receptor bending
- D Improper patient head tilt
Correct answer: Incorrect horizontal angulation
Incorrect horizontal angulation prevents the beam from passing between teeth. This causes overlapping and reduces diagnostic value.
Which technique is most appropriate for imaging large areas of the mandible or maxilla?
- A Bitewing
- B Periapical
- C Occlusal
- D Panoramic
Correct answer: Occlusal
Occlusal radiographs capture broad anatomical areas. They are useful when standard periapical films cannot be positioned.
What is the primary purpose of the full-mouth radiographic series (FMX)?
- A Detect interproximal caries only
- B Evaluate craniofacial growth patterns
- C Assess all teeth and supporting bone
- D Record TMJ movement during function
Correct answer: Assess all teeth and supporting bone
An FMX shows all teeth and their supporting structures. It is used for comprehensive evaluation.
Which radiograph is most appropriate to evaluate the eruption pattern of an impacted canine?
- A Bitewing
- B Occlusal
- C Periapical
- D Panoramic
Correct answer: Panoramic
A panoramic radiograph shows developing teeth and their positions. It is excellent for locating impacted teeth.
Which error is caused by insufficient vertical angulation in periapical radiographs?
- A Foreshortening
- B Elongation
- C Overlap
- D Film fog
Correct answer: Elongation
Elongation occurs when the beam is too flat relative to the tooth. Proper angulation prevents distortion.
Which radiographic technique requires the receptor to be placed as far from the teeth as possible?
- A Paralleling
- B Bisecting
- C Occlusal
- D Tangential
Correct answer: Paralleling
The paralleling technique requires distance between the tooth and receptor. Despite this, it reduces distortion due to the long PID.
Which type of radiograph is preferred to evaluate apical pathology?
- A Bitewing
- B Periapical
- C Panoramic
- D Occlusal
Correct answer: Periapical
Periapical radiographs show the entire tooth from crown to apex. They are essential for diagnosing root and periapical conditions.
During bitewing imaging, the receptor should be positioned to capture:
- A Only the maxillary posterior crowns
- B Only the mandibular posterior crowns
- C Crowns of both arches and crestal bone
- D Only the posterior tooth apices
Correct answer: Crowns of both arches and crestal bone
Bitewing films must show both maxillary and mandibular crowns as well as the crestal bone. This allows evaluation of caries and bone levels.
What is the correct head position for taking bitewing radiographs?
- A Frankfort plane parallel to the floor
- B Head tilted sharply upward
- C Head tilted sharply downward
- D Nose pointed toward the ceiling
Correct answer: Frankfort plane parallel to the floor
Keeping the Frankfort plane parallel ensures proper alignment. It helps avoid distortion in bitewing images.
Which technique helps reduce retakes by stabilizing receptor positioning?
- A Using finger-holding technique
- B Using receptor-holding instruments
- C Positioning the patient at an angle
- D Increasing exposure time
Correct answer: Using receptor-holding instruments
Holding devices improve accuracy and stabilization. They reduce movement and misalignment, lowering the need for retakes.
The lingual mounting method places the radiographs so that:
- A The viewer sees the patient from the front
- B The viewer sees the patient as if looking into the mouth
- C Roots appear reversed
- D The images are upside down
Correct answer: The viewer sees the patient as if looking into the mouth
Lingual mounting means the viewer is positioned behind the patient, looking outward. This follows the orientation of the patient’s anatomy.
Which radiograph is best suited for examining salivary stones?
- A Bitewing
- B Occlusal
- C Periapical
- D Panoramic
Correct answer: Occlusal
Occlusal films provide broad images of the floor of the mouth. They are ideal for detecting salivary stones in the submandibular duct.
Which factor is essential for producing diagnostic radiographs regardless of technique?
- A Frequent patient repositioning
- B Correct receptor and beam alignment
- C The shortest possible exposure time
- D Exclusive use of the bisecting technique
Correct answer: Correct receptor and beam alignment
Correct receptor placement and beam alignment ensure clear, accurate images. Even small errors can cause distortion or retakes.
Which image is most helpful in evaluating the relationship of the maxillary sinuses to the roots of maxillary molars?
- A Posterior bitewing
- B Maxillary occlusal
- C Periapical of molars
- D Panoramic radiograph
Correct answer: Panoramic radiograph
A panoramic radiograph provides a broad view of the sinus and molar root relationship. This helps assess sinus involvement in dental pathology.