DH103 Final Review

Which of the following will correct a foreshortened image?

Decreasing the vertical angulation

Each of the following statements regarding occlusal radiographs is correct EXCEPT one. Which one is the exception?

They image both of the arches on a single film

Each of the following is a use of an occlusal radiograph EXCEPT one. Which one is the Exception?

Detecting Incipient interproximal decay

The topographical occlusal radiographic technique is similiar to what technique?

Bisecting

Which of the following local contributing factors for periodontal disease will not be detected

Recession

The purpose of the embossed dot on the film packet is to:

distinguish the patient's right from left on the developed radiograph

The embossed dot will be used after the film is processed to aid in identifying the image as either the patient's right or left side

Which of the following restorative crown types appear the least radiopaque?

Porcelain

two indication that will help you in determining which way to mount bite-wing radiographs are 1. the curve of speed curves _____ toward the distal and 2. mandibular molars have _____ distinct roots

upward; two

when using the occlusal technique the receptor is portion with the ____ side facing the arch that is being exposed, and the receptor is place in the mouth _____

tube; between the occlusal surfaces of the maxillary and mandibular teeth

Each of the following is a possible location of caries EXCEPT one. Which one is the EXCEPTION

Alveolar

The ALARA concept implies that?

Any radiation dose that can be reduced without major difficulty, great exposure, or inconvience, then should be reduced or eliminated

You have a 4 year-old boy in your chair, which size receptor will you need to use to take bite-wing images on him?

Size 0

each of the following is an advantage of panoramic radiographs except one

a. panoramic radiographs are a simple procedure

b. they are less likely to cause patient discomfort

c. there is a decreased image distortion

d. there is a reduced radiation dose

there is a decreased image distortion

the greatest limitation of panoramic radiographs is the inability to

produce image sharpness

Cone Cutting of the radiographic image most likely results from an error made in which of the following steps?

Centering the x-ray beam

Overlapping of adjacent teeth on the radiographic image most likely results from an error made in which of the following steps?

Horizontal Angulation

When using the paralleling technique excessive vertical angulation will result in:

Cutting off the occlusal/ Incisal edges of the teeth

Which of these is NOT a normal radiographic landmark often imaged on intraoral radiographs

Occipital Bone

Which of the following structures of the tooth appears the most radiopaque?

Enamel

What is the thin radiopaque border that outlines the root of the tooth called?

Lamina Dura

Which of the following lists the structures in order of decreasing radiopacity?

Enamel, dentin, cementum, pulp

which of the following restorative materials appears the most radiolucent?

Silicate

For caries to be imaged on a radiograph, approximately what percentage of calcium and phosphurous of the tooth structure must be lost?

40-50%

The caries process demineralizes tooth structures, allowing black x-rays to through the tooth and blank the image receptor?

more, darken

Where are caries located?

occlusal surfaces, on buccal & lingual grooves of posterior teeth, & on lingual pits of the maxillary incisors

What is film emulsion composed of?

gelatin and silver halide crystals

What is involved in patient prep before taking an x-ray?

making sure the correct setting are selected on control panel, patient is wearing lead apron with thyroid collar attached

Which molars have three roots?

maxillary first and second molars

Which molars have two roots?

mandibular molars

What represents the correct order of film processing in an automatic processing unit?

Developer, fixer, wash, drying

Which are the majority of x-rays produced by dental x-ray machines?

Bremsstrahlung radiation

The purpose of a lead foil sheet in the film packet is

protect the film from backscatter radiation

what conditions must exist for X-rays to be produced

source of electrons, appropriate target material, a high voltage, and a vacuum

The more pixels in a digital image, the

higher the resolution and the sharper the image

what are the advantages of digital imaging?

instant viewing of the image, elimination of photographic process and darkroom, improved gray scale resolution, less radiation exposure to the patient, remote electronic consultation and sending of images, patient education

What does the radiographic appearance of calculus look like?

radiopaque notches on the tooth. typically will be on inter proximal surface.

Which regulating device on the control panel measures the amount of current passing through the wires of the circuit?

The mA selector

Positioning for premolar and molar bitewings:

MOST anterior caninePremolars: anterior edge of film is in-line with middle side of canineMolars: anterior edge of film is in-line with middle of 2nd premolar

When you are placing the film packet in your patients mouth, which side of the film packet would you place towards the patients teeth

The solid white side

The image receptor should be placed with the long dimension along the midline (front to back) for which of these occlusal radiographs

maxillary topographical posterior

Legally, radiographs are the property of

the dentist who originally prescribed the radiographs.

A latent image is

invisible image created after exposure but before processing

Actual caries depth is ______ than what you see on a radiograph

greater

Do you use negative or positive angulation when exposing mandibular arch vs maxillary arch?

Mandibular:negativeMaxillary: positive

SI unit for absorbed dose is the:

RAD

Direct radiation injury occurs when:

x-ray photons hit critical targets within a cell

Which of the following traditional units does not have an SI equivalent?

The Roentgen

Radiation injuries result from ____________or___________

ionization or free radical formation

Each of the following statements regarding informed consent is correct except one. Which one is the exception?

A) Speak to the patient in lay terms about the risks and benefits of exposing radiographs.

B) Allow the patient to choose who he or she wants to expose the radiographs.

C) Inform the patient about the risks of radiation exposure.

D) Inform the patient of the purpose of exposing the radiographs.

Allow the patient to choose who he or she wants to expose the radiographs.

Which film speed requires the least amount of radiation exposure to produce a diagnostic-quality image?

F-speed

From the following select the correct generalization that aids in mounting radiographs

Maxillary anterior teeth are larger than mandibular anterior teeth

Which statement(s) regarding film mounting is (are) true?

a. It allows the radiographs to be viewed in a systematic order

b. It helps to prevent lost films

c. It provides a means for labeling the films with pertinent data

d. All of the above

Anterior periapical radiographs should be positioned in the oral cavity with the long dimension ______, and posterior periapical radiographs should be positioned in the oral cavity with the long dimension ______.

verticle, horizontal

Which of the following is the correct reason that a cape-style lead barrier without a thyroid collar be used when exposing panoramic radiographs?

due to the position of the PID, the thyroid collar would block the x-rays

Excessive Verticle Angulation when using the paralleing technique results in

elongated images of the teeth

Which of the following will correct an elongated image?

increasing vertical angulation

film should be stored

stored on edge, away from chemical fumes, safe from radiation, exp date visible

To determine verticle angulation when using the bisecting technique the central ray of the xray beam should be directed

perpendicular to the imaginary bisector

Purpose of the periapical examination

to examine the entire tooth (crown and root) and supporting bone

Which image receptor placement is most likely to be more comfortable and allow the patient to become accustomed to the procedure

Maxillary anteriors

where should you start in your exposures and move in what direction

For ALL sections of mouth you will move anterior to posterior. (i.e bitewings: premolar exposure --> molar exposure & repeat)

what can cause slanted occlusal plane?

improper positioning of film packet

The film layer that contains the latent image is the:

Emulsion

The radiographer should do each of the following to aid in managing the apprehensive patient except one

Expose the more difficult posterior radiographs first

Safelighting is in the ________portion of the visible light spectrum

Red-orange

4 Layers of Film?

film base, adhesive layer, emulsion, protective layer

Increase kVp

increase density

decrease contrast

decrease kVp

increase contrast

decrease density

mA is directly associated with:

density ONLY

Horizontal bone loss:

bone destruction parallel to a line between CEJs of adjacent teeth

vertical bone loss:

Adjacent to one tooth, looks like a triangular notch. Can be associated with trauma from occlusion in the presence of plaque

Localized bone loss

occurs in isolated areas with less than 30% of sites involved

General bone loss

occurs evenly throughout dental arches, more than 30% of sites involved

How does gold appear on a radiograph?

radiopaque; smooth marginal outline

How does amalgam appear on a radiograph?

radiopaque; irregular outlines; overhang is seen beyond portion of the crown and in interproximal area

Gold crowns and bridges appear as:

large restorations with smooth contours and regular borders; radiopaque

Stainless steel restorations seen as:

radiopaque but not as dense; outlines are smooth & regular; see-through

How does porcelain appear on a radiograph?

slightly radiopaque and resembles dentin.

What is safe lighting used for?

removes short wavelengths in the blue-green portion of visible light spectrum that are responsible for exposing and damaging x-ray film

Why do you place the dot in the slot of a film holder?

to determine film orientation

When you should expose 4 horizontal posterior bite-wings:

When both molars and premolars are present

Where root caries located?

involve only roots of the teethAppears cupped-out /crater, radiolucent, below CEJ

Where are recurrent caries located?

occurs adjacent to preexisting restorations- this happens when a cavity was not properly cleaned before placement of restorative materialRadiolucent area beneath restorationsMost often occurs beneath the interproximal margin of restoration