SC10
Radiographic examination
Types of oral radiography machines
BITEWING X-RAYS
Types of oral radiograph examination
Characteristic of ideal radiograph picture
Equipments
Principles
Definition and function
Radiation protection
Radiation protection measure
Law and regulations of radiation protection in Indonesia
Radiation
Effects of radiation
Dose and dosimetry
Process of radiation
Definition and function
Types of radiation beams
Radiation is the transfer of energy from one medium to another. Particles or electromagnetic waves that are used to release energy.
Function
types
Ionizing radiation
Non-ionizing radiation
In humans used to diagnose, monitor, and treat a variety of metabolic processes and disease disorders
The use of x-rays, a sort of radiation that may pass through human skin, is the most prevalent of these medical treatments.
Nuclear materials are used in course work, laboratory demonstrations, experimental research, and a range of health physics applications at universities, colleges, high schools, and other academic and scientific institutions.
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Radiation works by damaging genes (DNA) in cells where they have the function in controlling cell growth and division. When they damage genes of cancer cells, cancer cells are not able to grow and divide any more, and over time, the cells die.
Radiation first kills the cells that are active in cell division. However, the amount and the type of radiation that reaches the cell and their speed in growing affect whether and how quickly the cell will die or be damaged.
In X-rays, a stream of electromagnetic radiation interacts with an anode in an x-ray tube. The x-rays that are made by this interaction are being directed towards the part of the body that is to be examined. When they contact out body tissues, an image is produced on a metal film.
Soft tissues like skin and also organs are not able to absorb the high-energy rays and the beam passes through them. While dense materials like the bones absorb the radiation.
In dental radiography, image was produced from the X-rays that are passing through the patient and interacting with the photographic emulsion on a film, resulting in blackening of the film. Film is then gradually replaced by a variety of digital sensors with the image being created in a computer. The parts of the digital sensors that have been hit by the X-rays appear black in the computer-generated image, and the extent to which the emulsion or the computer-generated image is blackened depends on the number of the X-rays that reached the film or the sensor.
Radiation-absorbed dose (D)
Equivalent dose (HT)
It is a measure of the amount of energy absorbed from the radiation beam per unit mass of tissue and can be measured using a dosimeter.
It is a measure which allows the different radiobiological effectiveness (RBE) of different types of radiation to be taken into account.
beta particle
Equivalent dose (HT)
Effective dose (E)
For X-rays, the radiation weighting factor WR = 1, therefore the equivalent dose (HT) in a particular tissue, measured in Sieverts, is equal to the radiation-absorbed dose (D), measured in Grays.
This measure allows doses from different investigations of different parts of the body to be compared, by converting all doses to an equivalent whole body dose
Collective effective dose or collective dose
This measure is used when considering the total effective dose to a population, from a particular investigation or source of radiation, and is measured in man-sieverts (man-Sv).
Hair
Brain
The losing of hair quickly and in clumps occurs with radiation exposure at 200 rems or higher.
they won't be damaged directly unless the exposure is 5,000 rems or greater
Thyroid
In sufficient amounts, radioactive iodine can destroy all or part of the thyroid
Heart
ntense exposure to radioactive material at 1,000 to 5,000 rems would do immediate damage to small blood vessels and probably cause heart failure and death directly.
Blood system
When a person is exposed to around 100 rems, the blood's lymphocyte cell count will be reduced, leaving the victim more susceptible to infection
Reproductive Tract
Because reproductive tract cells divide rapidly, these areas of the body can be damaged at rem levels as low as 200. Long-term, some radiation sickness victims will become sterile.
Long Term Effects on Humans
Long after the acute effects of radiation have subsided, radiation damage continues to produce a wide range of physical problems. These effects- including leukemia, cancer, and many others- appear two, three, even ten years later.
a neutron
alpha particle
electromagnetic radiation
Definition
Function
Radiographs (dental X-rays) are images of the teeth that dentists use to assess the overall oral health.
X-rays are used by dentists to detect damage and disease that aren't obvious during a clinical dental checkup.
Optimization
Dose limitation
Justification
• Positioning arms
• A control panel and circuitry.
• A tube head
Intraoral
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A tubehead
Positioning arms
A control panel and circuitry
extraoral
Advantage
disadvantages
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Can be used to determine the status of periodontal tissue and is effective for viewing interproximal calculus
As compared to the periapical x-rays, this radiographic more accurately shows the extent of bone destruction
Can detect an early caries
The crest of the alveolar bone is clearly visible
Safe for patients with high gag reflex
The periapical and root tips were not visible and the patient had difficulty occlusion of the maxilla and mandible so that the mouth was kept open
Nature of the radiographic image
Periapical X-Rays Paralleling technique
Advantage
disadvantages
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Images are generated geometrically accurate with small magnification
The periodontal bone plains are well displayed and periapical tissue is shown accurately with minimum elongation
Caries can be detected because the tooth crown is clearly visible
Radiographs can be reproduced at any time during different visits and operators
Relative position can be maintained between film, tooth and X-ray beam, has no effect on the patient's head (Whaites, 2009)
The long axis of the tooth and recording the image receptor plane can be visually located making it easier to adjust precise x-ray (Thomson & Johnson, 2012).
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The position of the holder grip in the mouth can make it difficult for operators who are inexperienced
The holder grip is disposable (Whaites, 2009)
Positioning the handle in the area of the third molar can be very difficult
Image receptor placement may be difficult to be accepted in certain patients: children, adults with small mouths, low palatal arch, or presence of tori, patients with sensitive mucosa, or high gag reflex edentulous
May increase patient discomfort when image receptors affect oral tissues (Thomson & Johnson, 2012)
Periapical X-Rays BISECTING technique
Advantage
disadvantages
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More comfortable since the film is placed in the mouth at an angle to the long axis of the teeth, the film doesn’t impinge on the tissues as much.
A film holder, although available, is not needed. Patients can hold the film in position using a finger.
No anatomical restrictions, the film can be angled to accommodate different anatomical situations using this technique
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More distortion, because the film and teeth are at an angle to each other (not parallel) the images will be distorted (see next slide).
Harder to position the x-ray beam, due to the film holder is often not used, so it is difficult to visualize where the x-ray beam should be directed.
The film is less stable such as using finger retention, the film has more chance of moving during placement
Digital Imaging
Advantage
disadvantages
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Saves time
Instant viewing of the image
Improved grayscale may aid in diagnosis
Less radiation dose to the patient
Potential to improve the image without reexposing the patient (density and contrast may be improved via software manipulation)
Electronic transfer of images through the internet speeds communication between practitioners and insurance companies
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Reliability of computer-stored patient records; the possibility of malfunction and record loss
Timing of when to purchase equipment; rapid technology advancements may make equipment obsolete in a relatively short time
Difficulty placing wired sensors intraorally
Initial investment cost
The difficulty of ideal hard sensor placement on some patients due to sensor bulk and size
Infection control of sensors
X-RAYS
Advantage
disadvantages
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The amount of radiation a patient is exposed to is quite small
Dangers associated with dental X-rays are extremely low
Affordable (cheaper) and simple technique
X-rays are not absorbed very much by air, hence specimen need not be in an evacuated chamber
Helps diagnose tumors easily without the need for surgery
Often used by radiologists to identifies cracks, infections, levels of injury, and abnormalities (bones)
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It does not provide 3D information.
Bones can block significant diagnostic data as it absorbs the radiation.
They do not interact very strongly with lighter elements
Due to its radiation, it mutates cells which causes ionization. This often leads to cancer
It does not produce the best image but a medium-quality image
The limitations imposed by a two-dimensional image and superimposition
Quality of the radiographic image
Perception of the radiographic image
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"ALARA" is the radiation safety guiding principle.
ALARA stands for "As low as reasonably achievable."
This principle states that even if the dose is small, you should try to avoid it if it offers no immediate benefit.
To do so, you can utilize three important radiation safety measures: time, distance, and shielding.
Time
Distance
Shielding
ACT NO. 10/1997 on Nuclear Energy: Chapter 5 Regulatory
ACT NO. 10/1997 on Nuclear Energy: Chapter 5 Regulatory
Goverment Regulation
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GR No. 2/2014 on the Licensing of Nuclear Installation and the Utilization of Nuclear Materials
GR No. 61/2013 on Radioactive Waste Management;
GR No. 54/2012 on the Safety and Security of Nuclear Installations;
GR No. 46/2009 on the Liability of Nuclear Damages;
GR No. 29/2008 on the Licensing of Ionizing Radiation Sources and Nuclear Materials.
GR No. 33/2007 on the Safety of Ionizing Radiation and Security of Radioactive Sources. (adapting the IAEA BSS-115).
GR No. 26/2002 on the Transport Safety of Radioactive Materials (to be amended soon);
BAPETEN Chairman Regulation
BCR No. 1/2009 on the Provision of Physical Protection of Nuclear Installation and Materials
BCR No. 7/2007 on the Security of Radioactive Sources.