SEMINARONRADIATION PROTECTION

ByDr Saloni

Contents

IntroductionPatient exposureOperator exposureRadiation exposure guidelineRadiation protection and patient educationConclusionReferences

Introduction Many of the early pioneers in dental radiography suffered from the adverse effect of radiation like they lost their fingers, limbs & ultimately their lives to excessive doses of radiation. The hazards of radiation are now well documented & radiation protection measures can be used to minimize radiation exposure to both dental patient & dental radiographer. Goal The goal of dental radiography is to obtain useful diagnostic information while keeping radiation exposure to the patient and dental staff to a minimum.Patient protection X-radiation causes biologic changes in living cells & adversely affects all living tissue. With the use of proper patient protection techniques ,the amount of x-radiation received by dental patient can be minimized. patient protection techniques are- Before exposure During exposure After exposure

Before exposure Prescribing dental radiographs Proper equipment Filtration CollimationPosition indicating -device The person who responsible for prescribing dental radiographs is the dentist. The dentist uses professional judgment to make decision about the number, type & frequency of dental radiographs Proper equipment Use of proper equipment helps in limiting the amount of x-radiation to a dental patient. The tube head equipped with appropriate Aluminum filter, Lead collimator & Position indicating device Filtration The use of radiation absorbing material for selectively attenuated or screening out the low energy x-ray from the primary beam of x- radiation.Two types Inherent filtration. Added filtration

Inherent filtration. When primary beam passes through Glass window of x-ray tube , The insulating oil Tube head seal . The inherent filtration of the dental machine -0.5-1.0mm of aluminum disk Added filtration Placement of aluminum disks in the path of the x-ray beam between the collimation & the tube head seal in the dental x-ray machine .The purpose of the aluminum disks is to filter out the longer wave length ,low energy that are harmful to the patient & also not useful in diagnostic radiography.Filtration of x-ray beam results in a higher energy & more penetrating useful beams Total filtration inherent plus added filtration Total filtration state & federal laws regulates the required thickness of total thickness (inherent plus added filtration) .Dental x-ray machine operating at or below 70 kilo voltage require minimum total of 1.5 mm aluminum filtration .Machine operating above 70 kilo voltage require a minimum total of 2.5 mm aluminum filtration

Collimation in radiology, The collimation is the elimination of the more divergent portion of an x-ray beam Restrict the size & shape of x-ray beam Reduce the patient exposure A collimator or lead plate with a hole in the middle ,fitted directly over the opening of the machine housing where the x-ray beam exit the tube head Types of collimator Circular or round Rectangular collimator slightly larger than size 2 intraoral film reduces patient exposurePosition indicating device Position indicating device ( PID) ,or cone, appears as an extension of the x-ray tube head & is used to direct the x-ray beam . Basically three types of PID -Conical -Rectangular -Round Position indicating device Conical PID appears as closed ,pointed plastic cone When x-ray exit from the pointed cone, they penetrate the plastic and produce scatter radiation.Conical PID no longer used in dentistry Open ended and lead lined rec tangular or round PID are used They do not produce scatter radiation Both are typically available in two length Short -8 inch Long -16 inchLong PID is preferred because less diversion X- ray beam occurred.Most effective in reducing patient exposure is rectangular type .During exposure Patient protection measures are used during x-ray exposure as well as before exposure. Thyroid collar Lead apron Fast film Film holding devices Exposure factor selection Proper technique All these devices used during exposure to limit the amount of radiation

Thyroid collar Thyroid collar is a flexible lead shield that is placed securely around the patients neck to protect the thyroid gland from scatter radiation. Thickness -0.2mm. It protect the highly radiosensitive tissue of thyroid gland its use is recommended for all intraoral film And not recommended for extra oral film Lead apron The lead apron is a flexible shield placed over the patients chest & lap to protect the reproductive & blood forming tissues from scatter radiation .It is use in all intraoral & extra oral films Fast film Fast film is the most effective method of reducing a patients exposure to x- radiation It is available for both intraoral & extra oral radiography Before F-speed film, E-speed or Ekta speed was the fastest film It provides 20% reduction in exposure than E-speed film Film holding devices It is also effective in reducing a patients exposure to x-radiation Stabilizing the film in the mouth Reduces the chances of movement Patients finger is not exposed to unnecessary radiation From book types of film holder Types of film holder Xcp bite block Stable bite block Precision film holder restrict the size of the x-ray beam Exposure factor selection It also limits the amount of x-radiation .The dental radiographer can control the exposure factors by adjusting The kilo volt age peak Milli amperage Time Like setting of 70kvp to 90 kvp keeps patient exposure to a minimum Proper technique Proper techniques helps to ensure the diagnostic quality of films & to reduce the amount of exposure .Films that are nondiagnostic must be retaken .To produce diagnostic film the radiographer must have a thorough of technique After exposure The radiographer should not end the x-radiation during exposure After the film have been exposed, they must be Proper film handled & processed Proper film handling Proper film processing Proper film handling Proper film handling is necessary to produce diagnostic radiograph & to limit patient exposure From the time the films are exposed they are processed careful handling should taken Artifact caused by improper film handling result in nondiagnostic films .Proper film processing is also necessary to produce diagnostic radiograph & to limit patient exposure to x-radiation Automatic film processors Operator protection Protection Guidelines Distance recommendation Position recommendation Shielding recommendation Radiation Monitoring Equipment Monitoring Personnel Monitoring Radiation worker Classified worker Require compulsory personal monitoringRequire compulsory annual health check upReceive high level of exposure Non classified worker Receive low level of exposureNo personal monitoringProtection Guidelines The purpose of operator protection guidelines is to provide the dental radiographer with the basic safety information during working with x- radiation Distance recommendation Maintain an adequate distance during exposure.The dental Radiographer must stand at least 6 feet away from the x-ray tube head during x-ray exposure. When maintaining this distance is not possible ,a protection barrier must be used Position Recommendation This is the the 2nd thing for operator to avoid the primary beam which travels in a straight line .The dental radiographer must be positioned perpendicular to the primary beam like 90 degree -135 degree angle to the beam Proper operator position also includes Radiographer must never hold a film Radiographer must never hold the tube head Shielding recommendation Radiation Monitoring It also used to protect the dental radiographer & includes the monitoring of both equipment & personnel it can identify occupational exposure The use of radiation monitoring can identify excess occupational exposure Equipment Monitoring Leakage radiation is an exception of the primary beam emitted from the dental tube head .If a dental x-ray tube head has faulty tube head seal ,leakage radiation results.Dental x-ray equipment monitored for leakage radiation through the use of film device that obtained from manufacturers of dental x-ray equipment Personnel Monitoring The amount of x-radiation that reaches the body of the dental radiographer can be measure through the use of a personnel monitoring device known as a film badge.It is obtained from film badge service company .The film badge consists of a piece of radiographic film in a plastic holder Each radiographer should worn their badge at waist level when exposing x-ray films Advantage of film badges1. Provide permanent record of dose received2. May be rechecked or reassessed3. Simple and inexpensive Disadvantage of film badges1. No immediate indication2. Processing is required which may lead to error

When film badge not worn should store in radiation safe area Should never worn when radiographer is undergoing x- ray exposureAfter the dental radiographer has worn the film badge for a specified interval (1 week ,1 month),the badge return to service company .The service company give the report for each radiographer .Radiation exposure guidelines All x-radiation is harmful .To protect the patient & operator from excess radiation exposure, radiation exposure guidelines have been established .It includes Radiation safety legislation Maximum permissible dose Maximum accumulated dose Radiation safety legislation Principles1. No X ray if no positive net benefit2. ALARP exposure as low as reasonably practicable3. Dose equivalent not to exceed the limit recommended Radiation safety legislation have been established at both the state & federal level to protect the patient ,operator & general public from radiation hazards Maximum permissible dose(MPD) Means maximum dose of radiation that an individual can receive The national council on radiation protection (NCRP) defined as measurement of maximum dose equivalent that a body is permitted to receive in a specific period of time The MPD is the dose of radiation that the body can endure with little or no injury According to most recent report in 2003 the current MPD for occupationally exposed person ( dental radiographer ) is 5.0 rems /year ( 0.05sv/yr).Where as non occupationally exposed person ,the current MPD is 0.1 rem/yr ( 0.001sv /yr) Maximum accumulated dose(MAD) Occupationally ,exposed workers must not exceed an accumulated lifetime radiation dose .MAD is determined by a formula based on workers age formula is MAD=( N-18) *5 rems /year MAD=( N-18) *0.05 Sv /year where N is persons age in years Radiation protection & patient education Patient often have question about radiation exposure .The dental radiographer must be prepared to answer such question & to explain exactly how patients are protected before, during & after x-exposure.Before start say to patient Protect you from unnecessary radiation. The dentist custom order your x-ray based on your individual needs The x-ray equipment which are in use are frequently tested

Radiation protection & patient education During x-ray exposure Use Thyroid collar & lead apron to protect the body from excess radiation The fastest film Film device to hold the film so that finger are not exposed Good technique Conclusion Unnecessary recommendation to undergo x- ray is unethical Monitoring is essential to keep the exposure within the recommended limits Radiation protection is like careful use of advantage of x - ray Reference DENTAL RADIOGRAPHY BY HARING HOWERTONDENTAL RADIOGRAPHY AND RADIOLOGY BY ERIC WHAITESORAL RADIOLOGY BY WHITE AND PHAROAH