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DA105RADIOLOGY

RADIATION HEALTH AND SAFETY

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• 1968 – Radiation Control for Health and Safety Act – Standardized xray equipment; required filtration, collimation, quality control programs

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• 1981 – Consumer – Patient Radiation Health and Safety Act – Each state must monitor and regulate, in it’s Dental Practice Act who is allowed to take xrays and the training for that person

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Radiation comes from 2 sources

• Natural Background radiation – earth, sun, atmosphere

• Artificial – Diagnostic and therapeutic, atomic testing, scientific experimentation

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CHARACTERISTICS OF DENTAL XRAYS

Positive• Decay• Cysts• Infection• Retained roots• Foreign bodies• Tooth development• Growth irregularities

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Negative• Can penetrate tissues

that are radiosensitive• Ionize change, or alter

tissues• Most sensitive tissue –

Growing or immature cell tissue

7Tissues which are radiosensitive FROM MOST TO LEAST

• Embryonic tissue (in Pregnant women_• Blood and bone marrow• Skin• Connective tissue• Nerve• Brain• Muscle cells• Bone• enamel

8CUMULATIVE EFFECT

• Long lasting effects from exposure which can add up to harmful amounts.

• SCATTER RADIATION – Remains in cells but the body can slough it off in 24-48 hours

• Repeated exposure does not give the body enough time to slough off the damaged cells and permanent tissue damage can occur

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LATENT PERIOD

• The time from exposure to xray until there is observable damage

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SHORT TERM EFFECTS

• Short term effect from high doses lead to biological damage– High Doses (nuclear accident) can cause

erythema and epilation. Dental xrays are not high dose, not possible at xray machine settings

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LONG TERM EFFECTS

• Long term effects chronic after years of exposure. Ex. Operator hold xray in patient mouth = dermatitis and subsequent development of cancerous lesions of finger

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OTHER LONG TERM EFFECTS

• Erythema• Epilation• Split fingernails• Blindness• sterility

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• Any exposure to radiation conveys potential risks, even low dose such as dental xray.

• It’s important for a DA to learn critical organs because radiation safety is directed at minimizing exposure to highly sensitive organs

14CRITICAL ORGANS

• Hematopoietic – function and form of blood elements

• Thyroid gland - cancer• Breast- cancer• Salivary glands – sublingual, submandibular,

parotid

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• Reproductive organs – male and female • Pregnancy – genetic effects, changes in

reproductive cells, leads to radiation-induced mutations

• Skin – early aging• Lens of eyes – cataracts – have patient close

eyes

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Pregnant Patient

• Do not take x rays on pregnant patients unless emergency

• OBGYN must approve all exposures

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SECONDARY

• Radiation coming from or bounce or deflection off soft tissue, patient’s head, lead materials, cone apron

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SCATTERED

• Radiation deflected by impact with matter (object); travels to all parts of body and all over the room; undesirable xrays

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SAFETY PRECAUTIONS

• ALARA• As Low as Reasonably Achievable (National

Committee on Radiation Protection 1971• Maximum diagnostic benefit with minimum

exposure possible determine if radiation is preferable agent for making diagnosis.

• Avoid retakes/check to see if current xrays exist before taking one

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FILTRATION

• Removes non-useful, low energy soft radiation from primary beam. Aluminum disc placed at window

• Federal Law – 1.5 mm aluminum filter at 50-70 KvP. 2.5 mm Above 70 KvP

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COLLIMATION

• Restricts size of beam by use of lead lined PID

• One of the most important ways to minimize patient exposure

• Federal law – dental xray can be no more than 2.75 inches at patient face

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CONTINUING EDUCATION

• Learning about new procedures and discoveries

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CARDINAL PRINCIPLES

• 1. Use least amount of radiation that is needed

• 2. Operator never hold film for patient

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EFFECTS OF ORAL RADIATION THERAPY

• Xerostomia dry mouth• Dysphagia difficulty in swallowing• Radiation caries caused by lack of saliva

from xerostomia• Osteoradionecrosis – death of alveolar bone• Inflammed gingiva• Mobility of teeth• Loss of appitite