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RADIATION HAZARDS&PROTECTION

RADIATION HAZARDS&PROTECTION. DR SAMY I ALAGHA A.PROFESSOR OF RADIOLOGY ALAZHAR GAZA UNIVERCITY. EFFECT OF RADIATION. 1- DIRECT EFFECT: The energy of x-ray photons is directly transferred to biological macromolecules 2-INDIRECT EFFECT:

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RADIATION HAZARDS&PROTECTION

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  1. RADIATION HAZARDS&PROTECTION DR SAMY I ALAGHA A.PROFESSOR OF RADIOLOGY ALAZHAR GAZA UNIVERCITY

  2. EFFECT OF RADIATION 1-DIRECT EFFECT: The energy of x-ray photons is directly transferred to biological macromolecules 2-INDIRECT EFFECT: The energy of x-ray photons is absorbed by water in a biological system

  3. RADIOLYSIS OF WATER H2O + X-RAY >>>>>H+ + OH- (Free radical) H + O2(In tissues)>>>HO2(Hydroperoxyl radical) HO2 + H >>>>H2O2(Hydrogen peroxide)

  4. RADIATION UNITS 1-Roentgen (R) Unit of X-ray exposure 2-Rad Unit of absorbed dose 3-Rem Unit of biological damaging effect

  5. RADIATION UNITS

  6. Radiation Effect on oral tissue A-Short term effect Depend on sensitivity of cells B-Long term effect Fine vessels>>swelling>>>>degeneration&necrosis>>>progressive fibrosis>>>narrowing&oblitration of vascular lumen

  7. EFFECT OF RADIATION ON ORAL TISSUE 1-ORAL MUCOUS MEMBRANE AFTER 2 WS OF RADIATION>>Mucositis(redness) Later >>>white/yellow pseudomembrane>>>severe discomfort&difficut food intake • Good oral hygiene as socondry infection(candida) • Healing after 2 months • On long term>>>atrophy of MM

  8. EFFECT OF RADIATION ON ORAL TISSUE 2-TASTE BUDS • Radiotherapy>>>degeneration of taste buds>>> Loss of taste(in 2nd or 3rd week} • Recovery 2-4 months after radiotherapy

  9. EFFECT OF RADIATION ON ORAL TISSUE 3-SALIVARY GLANDS • Within few ws of radiotherapy>>>loss of salivary secretion>>>dry mouth(xerostomia)>>tender mouth&difficult swallowing • After 6-12 months >>improvement due to compunsatory hypertrophy. • Xerostomia for more than 1y>>no recovery

  10. EFFECT OF RADIATION ON ORAL TISSUE 4-TEETH • Adult teeth are resistant to radiation effect • Pulpal tissues undego fibro-atrophy • Radiotherapy in children>>>retarted growth • Radiotherapy before calcification>>destroy tooth bud • Radiotherapy after calcification>>>malformation of teeth

  11. EFFECT OF RADIATION ON ORAL TISSUE 5-RADIATION CARIES This is due to less saliva and decrease PH &increase viscosity of saliva This is treated by topical 1%sodium fluoride gel

  12. EFFECT OF RADIATION ON ORAL TISSUE 6-BONE • Radiation induced fine vasculitis>>>bone infection &necrosis especially after teeth extraction • Osteo-radionecrosis occurs more in mandible than maxilla • In oseo-radionecrosis >>defined border between necrotic and normal bone without subperiosteal new bone formation • Post radiotherapy teeth extraction should be avoided

  13. X-RAY PROTECTION THIS IS DONE BY 1-Safe equipment 2-Proper technique 3-Professional judgement

  14. SAFE EQUIPMENT 1-Filtration 2-Collimation 3-Timer 4-Cones:opened ended &closed ended 5-Film speed 6-Leaded apron&thyroid collars 7-Film hold device

  15. PROPER TECHNIQUE 1-Proper film placement 2-Proper x-ray adjustment 3-Proper processing

  16. PROFESSIONAL JUDGMENT

  17. OPERATOR PROTECTION 1-Protection from 1ry radiation 2-Protection from 2ry radiation 3-Protection from leakage radiation

  18. ENVIRONS PROTECTION • They include secretaries and cleaners • Maximum permissible dose (M.P.D)=0.5rem/y • Protection is achieved by: 1-Shields 2-radiation survey&monitoring 3-1ry beam direction&patient position

  19. END

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