XRay - Outcome 2

Question 1

ALARA principle

Answer 1

The ALARA (“as low as reasonably achievable”) concept states that all exposure to radiation must be kept to a minimum. To protect both patients and operators, every possible method of reducing exposure to radiation should be employed to minimize risk. The radiation protection measures detailed in this chapter can be used to minimize patient and operator exposure, thus keeping radiation exposure “as low as reasonably achievable (Iannucci & Howerton, 2022) .”

Question 1

Three personal monitoring devices of x-radiation are the:

Answer 1

Film badge – a badge that is to be clipped on the body as per the manufacturer’s direction

Pocket dosimeter – usually the size of a pen and can be read by the person wearing it

Thermo luminescent devices (LTD) – come in various forms; based on crystals that are energized through x-radiation that give off light when heated (Robinson, 2024).

Question 2

Film Badge

Answer 2

The film badge is the most common type of monitoring system used. The badge is labeled and tracked through your social insurance number. It consists of an x-radiation-sensitive receptor with varying levels of sensitivity which records exposure (Robinson, 2024). On regular intervals, at the end of the reporting period, the badge is sent in to be read. These results are compared to the previous reports and are kept on file at the monitoring service company. A copy of this report is forwarded back to the dental office.

In the Province of Alberta, all professionals who participate in radiological procedures are required to wear a personal dosimeter (Alberta Government, 2021). Quality control procedures for equipment will be discussed later.

Question 3

2 biological effects of x-radiation

Answer 3

The biological effects can be identified as somatic or genetic

Question 4

Somatic

Answer 4

Somatic is exposure to radiation that causes a direct effect. Meaning the effect is not passed on to future generations. This is causing an effect on the irradiated cells in the body except for the reproductive cells (Iannucci & Howerton, 2022).

Injury to the individual

Reddening of the skin, pigmentation of the skin

Scales or ulcerations

Nausea, vomiting, diarrhea

Loss of hair

Cataracts

Cancer

Leukemia

Life-span shortening

Question 5

Genetics

Answer 5

Genetics is the changing of the reproductive cells through radiation exposure. These changes can be transferred to succeeding generations via reproductive cells (sperm/ova).

Injury to future generations

Radiation-induced mutations

Question 6

latent period

Answer 6

the time lag between the radiation exposure and the signs and symptoms of biological damage

Question 7

Risk versus Benefit Concept - for x-radiation

Answer 7

Risk versus Benefit Concept

There are some risks associated with the use of imaging radiation in dentistry. However, the levels of radiation involved in dental radiography are very low and are directed to a much-localized area. The benefit of detecting disease, which might otherwise go undetected, far outweighs the risk of receiving a small dose of x-radiation (Iannucci & Howerton, 2022). Next to the elimination of unnecessary X-ray examinations, the most significant factor in reducing patient dose is ensuring that examinations are performed using the proper technique. It is the responsibility of the dental assistant and the prescribing dental practitioner to be aware of this and to know how to carry out a prescribed examination with the lowest practical dose for the patient (Health Canada, 2022). The supervising professional is responsible for evaluating each patient’s needs when exposing radiographs.

Question 8

Protection for the Patient during xrays

Answer 8

A dental assistant must not perform any X-ray procedures unless it has been prescribed by the prescribing dental practitioner responsible for the patient (Health Canada, 2022).
The dental X-ray examination of a patient should be based on the history and clinical evaluation of the patient and should be to obtain diagnostic information, provide safe and efficient treatment, or monitor patient treatment (Health Canada, 2022).

Routine or screening examinations using dental X-rays, in which there is no prior clinical evaluation of the patient and no clinical justification, should not be performed, including examinations of children to monitor dental development. Dental X-ray examinations should only be performed after a clinical examination of the patient has determined an expected health benefit to the patient (Health Canada, 2022).
The possibility of performing non-radiographic examinations should first be considered. It should be confirmed that no previous X-ray images are available, which would avoid additional X-ray exposures (Health Canada, 2022).
The number of radiographic views required in an examination must be kept to a minimum, consistent with the clinical objectives of the examination
The dose to the patient must be kept to the lowest practical value, consistent with clinical objectives, and without loss of essential diagnostic information (Health Canada, 2022).
If there are selectable image resolution settings, for each image the lowest possible resolution setting that will meet the clinical objective should be used, as this can significantly reduce the dose received by the patient (Health Canada, 2022).
Radiological examinations of children must be performed using optimized techniques that have been modified for size and age (Health Canada, 2022).
Dental X-ray equipment must be maintained and monitored routinely through a Quality Assurance program and preventative maintenance, including routine monitoring of the quality of radiographs to ensure that they satisfy diagnostic requirements with minimal radiation exposure to the patient (Health Canada, 2022).
All images captured, whether on film or digital imaging systems, must remain with the patient records unless they are rejected by the operator for valid predefined quality issues. All rejected images must be collected for use during routine rejection/retake analysis (Health Canada, 2022).

Question 9

Pregnant or possibly pregnant persons - xray safety

Answer 9

Full consideration must be taken of the consequences of fetal irradiation.

It is generally accepted that the level of radiation to the fetus from dental X-rays is extremely low when the abdomen is not directly exposed (Health Canada, 2022).

For dental X-rays of pregnant patients, the Canadian Dental Association states that “Elective procedures may be deferred until after the pregnancy. Pregnant patients requiring essential and/or emergency treatment should receive the minimum number of radiographs needed for diagnostic purposes ” (Canadian Dental Association, 2005).

Question 10

Lead apron and thyroid collar use

Answer 10

Lead apron and thyroid collar use
The use of a thyroid shield is especially important in children, as the thyroid gland in children is particularly sensitive to radiation (Health Canada, 2022).
The patient must be provided with a thyroid shield when it will not interfere with the required diagnostic information for the examination (Health Canada, 2022).
The use of a lead apron is not required for the patient during routine dental X-ray procedures if all other recommendations for limiting patient radiation exposure are respected as the dose to the patient will not be significantly affected by abdominal shielding; however, a lead apron may be used to aid in patient comfort regarding fears of radiation (Health Canada, 2022).

Question 11

Collimation

Answer 11

Collimation
The X-ray beam must be well collimated and aligned with the patient’s head to restrict the beam as much as practicable to the area of diagnostic interest.
Rectangular collimation of the X-ray beam must be used for intra-oral examinations, except in occlusal protocols, as it significantly reduces the dose to the patient compared to circular collimation (Health Canada, 2022).

Question 12

Intra-Oral Examinations

Answer 12

A film/image receptor holder with an alignment device for the X-ray beam should be used (Health Canada, 2022).
A long cone (30 cm or longer) should be used, as it reduces the dose to the patient compared to a short cone (20 cm). The cone must ensure a minimum focal spot-to-skin distance of 20 cm (Health Canada, 2022)
For film-based imaging when the implementation of digital radiography is not practicable, E-speed film or faster must be used, and D-speed film must not be used (Health Canada, 2022).

Question 13

Protection for the Operator

Answer 13

any measure taken to protect the patient also protects the operator, but there are some “special” precautions to be observed by the operator.
Never hold films in the patient’s mouth during exposure.

Never stand in the direct path of the X-rays.
Stand as far as possible, at least 6 feet, from the source of radiation.

Never stay in an operatory to stabilize the tube head or PID during exposure.

Lead-lined walls and specially constructed partitions or lead screens afford excellent protection for the operator.

Utilize personnel monitoring devices for all staff members (dosimeter badges).

Routinely check all radiographic equipment to prevent “trouble” before it happens (quality assurance).

A periodic on-site survey will determine the output of the x-ray unit, radiation leakage, or any dangerous area by qualified radiation protection personnel.

Question 14

maximum permissible dose (MPD)

Answer 14

The most recent NCRP report states that the current MPD for occupationally exposed persons, or those who work with radiation (e.g., dental radiographers), is 50 mSv/year (0.05 Sv/year or 5.0 rem/year). It is recommended that dental radiographers not exceed a maximum dose of 50 mSv in any 1 year. For pregnant dental personnel, the radiation exposure limit is 0.5 mSv per month during the pregnancy months. For nonoccupationally exposed persons (i.e., the general public), the current MPD is approximately 1 mSv/year (0.1 rem/year).

Question 15

Cumulative Occupational Dose

Answer 15

Occupationally exposed workers must not exceed an accumulated lifetime radiation dose. This is referred to as the cumulative occupational dose. In the publication titled Limitation of Exposure to Ionizing Radiation NCRP Report 116, the NCRP has recommended that an individual’s cumulative occupational effective dose not exceed the worker’s age multiplied by 10 mSv. Thus for a 50-year-old worker, the NCRP would recommend a cumulative occupational dose of no more than 50 × 10 mSv = 500 mSv (0.5 Sv).

Question 16

dental X-ray equipment and facilities, as well as dental lasers are governed by?

Answer 16

Occupational Health and Safety Act and Code. (in the Province of Alberta) these documents specify that owners and staff have certain obligations to ensure the health and safety of themselves, their patients, and the public

Question 17

In dental radiography, a quality assurance program is defined as..

Answer 17

the planned and organized actions necessary to provide adequate confidence that dental X-ray equipment and related components reliably produce quality radiographs with minimum doses to patients and staff (Health Canada, 2022). A quality assurance program includes periodic quality control tests, preventive maintenance procedures, administrative methods, and training. It also includes continuous assessment of the efficacy of the imaging service and the means to initiate corrective action (Government of Canada, n.d.).

Question 18

As per Safety Code 30 (2022), the following four steps must be included in quality control procedures:

Answer 18

Equipment operation – It is essential that dental X-ray equipment and image processing and display equipment function properly before a quality assurance program is implemented.

Baseline performance – Baseline performance values of X-ray equipment and image processing system must be established after verifying that the equipment functions properly. This baseline performance will be used to diagnose any changes in equipment performance. It is important to keep records of equipment operation data and baseline performance measurements.

Reference test image – To evaluate image quality a reference test image is needed. This reference test image is made by using the X-ray equipment, image processing system, and a quality control phantom and will be used for comparison of quality control test images.

Result Evaluation and Action Levels – An effective quality control monitoring program includes not only a routine quality control testing schedule, data recording, and record-keeping, but also test result evaluation, such as the determination of acceptable or unacceptable limits of equipment operation coupled with a list of corrective actions that may be required.

Question 19

The following administrative procedure must also be included in a quality assurance program:

Answer 19

Responsibility
Record keeping
Evaluation of data
Limits of acceptability of data
Testing frequency
Corrective actions (Health Canada, 2022).

Question 20

Acceptance Testing

Answer 20

Acceptance testing is a process to verify compliance with the performance specifications of the X-ray equipment and that the equipment’s performance complies with federal and provincial regulations. Acceptance testing must be performed prior to any clinical use of the equipment. It is recommended that acceptance testing be performed by an expert with in-depth knowledge of the X-ray equipment, relevant regulations, and radiation protection principles. The owner may want the acceptance test to be performed by a person or organization that is independent of the manufacturer (Health Canada, 2022).

Question 21

Quality Control Testing Procedures and Equipment - Daily Quality Control Tests

Answer 21

Equipment warm-up - The manufacturer’s recommended warm-up procedure must be followed. The warm-up procedure must be repeated if the equipment is left idle for an extended period of time. It is important to note that all components of the imaging system that are routinely used must be warmed up, including computer display devices and printers (Health Canada, 2022).

Meters operation- Meters and visual and audible indicators should be checked for proper function (Health Canada, 2022).

Equipment conditions- X-ray equipment conditions should be visually inspected for loose or broken components and cleanliness. The X-ray source assembly should be checked for motion or vibration during operation. Visual inspection should also be conducted of all other components of the imaging system (Health Canada, 2022).

Darkroom cleanliness - In order to maintain the cleanliness of the darkroom, all working surfaces, tops of counters, and the floor should be cleaned daily (Health Canada, 2022).

Film processing- Film processor function must be evaluated every morning before performing clinical examinations after the processor has been turned on and has reached the required development temperature; and at other times as required, such as after a replenishment rate change (Health Canada, 2022).

Question 22

Monthly Quality Control Testing

Answer 22

Cassette, screen, imaging plate, and image receptor cleanliness and condition
Visual inspection of the cleanliness of imagining systems
Darkroom light conditions
Darkroom temperature and humidity conditions
film processor operation
Viewbox condition
Electronic display device performance
Digital image quality evaluation
Reject/retake analysis (Health Canada, 2022).

Question 23

Annual Quality Control Testing

Answer 23

These tests should be performed by the manufacturer or a service provider with appropriate expertise (Health Canada, 2022).

Question 24

What to tell patients before XRAY

Answer 24

“Before we get started, let me tell you just how our office does all that is possible to protect you from unnecessary radiation.
”
Before we expose you to any radiation, the dentist custom-orders your x-rays based on your individual needs. The X-ray equipment we use is tested to ensure that state and federal radiation safety guidelines are met.
“During x-ray exposure, we use a thyroid collar to protect your body from excessive radiation. We use a digital sensor or the fastest film available and a device to hold the receptor so that your fingers are not exposed to radiation. We also use proper technique so that we can avoid making mistakes that require further exposure.”

If using digital imaging: “Our office uses digital imaging procedures that reduce your exposure to radiation significantly compared with traditional, film-based radiography”

“Even after your dental images have been exposed, we take steps to process and handle the receptors carefully so that we don’t have to repeat any procedures.”

“Hopefully, this quick review of radiation protection techniques has answered some of the questions you may have about dental X-rays. What questions do you have before we begin?”

Question 25

image receptor

Answer 25

recording medium for an image - a digital sensor, a PSP, or a conventional xray film

Question 26

phosphorus storage plates (PSP)

Answer 26

reusable film-sized flexible plates coated with phosphorus as the image receptor

Question 27

Intra-Oral Xrays

Answer 27

The conventional film placed inside the mouth is referred to as intra-oral. Intra-oral films are direct exposure films.

Question 28

Extra-Oral Xrays

Answer 28

Films exposed outside the mouth are referred to as extra-oral radiographs.

This type of exposure is used when large areas of the jaw or skull need to be examined. Small periapical films cannot adequately cover the temporal-mandibular joint, the maxillary sinus, or broad areas of the jaw. However, extra-oral radiographs do not show details as well as periapical films.

Question 29

Intra-Oral Radiograph

Answer 29

1. Made intraorally.
2. Use direct-exposure x-ray film.
3. show individual teeth and surrounding bone.
4. Tooth images, especially with the paralleling technique, are closer to actual size.
5. Image outlined is usually more distinct and sharper.
6. Usually requires prolonged patient cooperation for a full mouth series.
7. It May require more time depending on the difficulty of the procedure and the cooperation of the patient.
8. By determining horizontal angulation for individual teeth, the contacts can be opened.

Question 30

Panograph

Answer 30

1. Made extra orally.
2. Use intensifying screens and screen-type x-ray film.
3. Show the entire facial complex on one film.
4. Due to increased distance between object and film, images are magnified.
5. Image outline on entire radiograph slightly fuzzy; spinal shadow may cause some loss of detail.
6. Usually requires less patient cooperation.
7. Usually can be completed within 5 minutes (from initial positioning of the patient to completion of exposure).
8. Usually produce overlapping of tooth contacts in the bicuspid and molar areas.

Question 31

Bitewing

Answer 31

image view that shows the crowns of both arches on one film

Question 32

digital image / direct digital xray

Answer 32

electronic signals captured by sensors and displayed on computer screen

Question 33

periapical xray

Answer 33

radiographic view that shows the crown, root tip (apex) and surrounding structures

Question 34

occlusal xray

Answer 34

radiographic view that shows large areas of the maxilla and mandible - the OCCLUSAL surfaces

Question 35

positioning instruments (XPC kit)

Answer 35

intraoral devices used to position and hold the film, sensor, or PSP