Term
| What affects the penetration ability of the x ray? |
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Definition
| KVP- affects quantity and quality |
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Term
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Definition
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Term
| What about kVp affects scatter radiation? |
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Definition
| The higher the Kvp, the less scatter is produced |
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Term
| How many impulses of radiation does an x ray unit produce per second? |
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Definition
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Term
| A radiograph show an amalgam overgang on a distal surface, what is the cause of this? |
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Definition
| Excessive condensed amalgam for the prep |
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Term
| Electrone carry energy from the cathode to the anode, what is most of the energy converted to in the target? |
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Definition
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Term
| Radiolucent pear shaped lesion is found distal to a maxillary right lateral incisor causing divergence of the lateral and canine roots. what is this? |
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Definition
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Term
Film sizes- Uses
Size 0
Size 1
Size 2
Size 3 |
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Definition
Size 0- Primary teeth
Size 1- adult ant PA
Size 2- posterior teeth & vertical bitewing
Size 3- XL BW
Size 4- occlusal |
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Term
| the MPD for occupationally exposed workers is |
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Definition
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Term
| Short scale of contrast is a result of |
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Definition
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Term
| Long scale of contrast is result of |
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Definition
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Term
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Definition
| Same lingual- Opposite Buccal |
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Term
| What are chemicals that make up developer? |
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Definition
| Elon & hydroquinone- turn exposed crystals into metallic silver |
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Term
| What is the chemical in fixer solution? |
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Definition
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Term
| Silver halide bromide crystals do what |
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Definition
| crystals on both sides of film that makes up the films emulsion layer |
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Term
| What factors increase density ? |
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Definition
| Milliamperage, exposure time, kVP |
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Term
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Definition
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Term
| What is the best way to reduce patient dose to radiation? |
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Definition
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Term
| Increasing kVP creates what type of contrast scale? |
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Definition
| Long scale- includes many shades of grey (low visual contrast) |
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Term
| What protects the patient best from scatter radiation? |
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Definition
| Lead apron- absorbs 90% of scatter that could have reached reproductive tissues |
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Term
| On a pano, if front teeth look big and fat, what happened? |
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Definition
| Anterior teeth were behind focal trough |
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Term
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Definition
| The duration for which x ray photons are produced by the x ray tube. It measured in fractions of a second. |
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Term
| The greater the exposure time, the _____ the image. |
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Definition
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Term
| Describe the inverse square law. |
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Definition
| the intensity of radiation is inversely proportional to the square of the distance from the source of radiation. |
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Term
| mA is directly proportional to the # of photons generated |
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Definition
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Term
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Definition
| Removes the low energy photons from the x ray beam. |
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Term
| What is the purpose of collimation? |
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Definition
| reduce patient exposure by restricting the size and shape of the x ray beam. |
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Term
| How is collimation achieved? |
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Definition
| using a lead plate with a central aperture, called a collimator. They can be round or rectangular. |
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Term
| What are the results of increased kVp? (5) |
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Definition
1. produces x rays with increased energy and shorter wavelength
2. increases penetrating power
3. is needed for larger patients with larger bones and more soft tissue
4. increased density
5. results in low contrast and long scale contrast |
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Term
| What is considered low kvp? What kind of contrast image result? |
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Definition
| 65-70. High contrast- short scale contrast |
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Term
| What is considered high kvp? |
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Definition
| 90. low contrast image results - long scale contrast |
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Term
| What factors influence density? |
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Definition
| kVp, mA, exposure time, thickness of a patient |
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Term
| What does density describe? |
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Definition
| Overall blackness of an image |
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Term
| Increased thickness in a patient yields a ______ image. |
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Definition
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Term
| An x ray tube is made up of what 3 parts? |
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Definition
| 1. Cathode 2. Anode 3. leaded-glass vacuum. Cathode and anode are located within leaded-glass vacuum. |
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Term
| Cathode consists of tungsten filament. Where is it situalted? |
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Definition
| In the negatively charged focusing cup |
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Term
| What does the tungsten filament do? |
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Definition
| It is heated and produces electrons. |
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Term
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Definition
| Converts the kinetic energy of the bombarding electrons into x rays. |
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Term
| The leaded glass vacuum tube prevents what? |
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Definition
| x rays from escaping in all directions. |
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Term
| What focuses the electrons into a narrow beam and directs the beam across the tube toward the tungsten target of the anode? |
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Definition
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Term
| X rays are generated when the beam is suddently stopped by the tungsten target. |
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Definition
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Term
| Describe the action of tungsten target. |
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Definition
| Stops electrons and converts the energy into x rays and heat. |
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Term
| Where is the tungsten target located? |
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Definition
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Term
| What is the action of copper stem? |
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Definition
| serves to dissipate the heat that is created with the production of x rays. |
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Term
| What is the main source of x radiation in a dental x ray machine? |
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Definition
| Bremsstrahlung Radiation. Accounts for 70% of total production of x rays. |
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Term
| Machines operating at or below 70 kv require how much aluminum? |
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Definition
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Term
| Machines operating above 70 require how much aluminum? |
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Definition
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Term
| what is the MPD of radiation for occupationaly exposed person? |
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Definition
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Term
| Is a round or rectangular PID more effective in reducing radiation? |
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Definition
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Term
| Is a short or long PID more effective in reducing radiation? |
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Definition
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Term
| What restricts the size and shape of x ray beam and reduces patient exposure? |
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Definition
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Term
| PID determines the target receptor distance |
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Definition
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Term
| Shorter PID results in ___ maginifcation. longer PID results in ___ magnification. |
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Definition
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Term
| In dental radiography, the most accurate image: |
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Definition
1. Uses the smallest focal spot size
2. shortest object-receptor distance
3. longest target receptor distance
4. central ray of x ray beam is perpendicular to the receptor and tooth
5. Receptor is parallel to the tooth. |
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