II.  Oral radiology


Oral radiology

1. The ‘heel effect’ results in

a. Low intensity X-ray beam on anode side of central ray

b. High intensity beam of X-rays towards cathode

c. Both of the above

d. None of the above

2. Half-value layer means

a. The rate at which an X-ray photon transfer its energy to irradiated matter

b. The thickness of a substance required to reduce the number of X-ray photons by half

c. The time taken for X-ray photons to travel half the distance from the source to the object

d. The heel effect

3. Which of the following rays exhibit the maximum penetration?

a. Alpha

b. Beta

c. Gamma

d. Electron beam

4. In the X-ray tube, X-rays are produced at

a. Focusing cup

b. Cathode

c. Walls of glass chamber

d. Anode

5. The quality of X-ray beam is governed by

a. KVP

b. mA

c. Filament current

d. Length of the X-ray tube

6. Reduction of the size of X-ray beam is achieved by

a. Filtration

b. Photo electric effect

c. Collimation

d. Bezold–Brucke effect

7. A film badge is a type of

a. Identification plate

b. Sonometer

c. Dosimeter

d. Tachometer

8. Filters of which metal are used to remove long wave length X-rays from the primary beam

a. Platinum

b. Aluminium

c. Copper

d. Lead

9. X-rays are discovered in the year

a. 1870

b. 1865

c. 1895

d. 1890

10. Which of the following is a rare earth element?

a. Lanthanum

b. Gadolinium

c. Terbium

d. All of the above

11. Which of the following is a commonly used collimating device?

a. Aluminium filter

b. Lead diaphragm

c. Molybdenum cup

d. Tungsten filament

12. Which of the following are most sensitive to X-ray radiation?

a. Tooth buds and salivary glands

b. Nerve and muscle tissue

c. Hair and nails

d. Cartilage

13. Which of the following is the most radioresistant organ?

a. Cartilage

b. Gonads

c. Lungs

d. Lymphoid

14. Complication of irradiation of mouth may include all except

a. Accelerated caries activity

b. Caries in unusual sites

c. Increased periodontal diseases

d. Xerostomia

1. c

2. b

3. c

4. d

5. a

6. c

7. c

8. b

9. c

10. d

11. a

12. a

13. a

14. c

15. Which of the following is the most radiosensitive cell?

a. Nerve cell

b. Lymphocyte

c. Muscle cell

d. Cartilage cell

16. The cells that are least susceptible to radiation are

a. Fibroblasts

b. Lymphocytes

c. Osteoblasts

d. Erythroblasts

17. Radiation causes cell death due to

a. Charring of nucleoproteins

b. Destroying their mitochondria

c. Ionization

d. Disruption of cytosol

18. Which of the following component of cell is most affected with radiation?

a. Cell wall

b. Cell membrane

c. Cytoplasm

d. DNA

19. Which of the following is the first complication following radiotherapy?

a. Mucositis

b. Candidiasis

c. Alopecia

d. Xerostomia

20. Osteoradionecrosis results from

a. Infection, trauma, radiation

b. Radiation, trauma, infection

c. Trauma, radiation, infection

d. None of the above

21. The medical speciality in which there is statistically higher incidence of leukaemia is

a. General surgery

b. Internal medicine

c. Radiology

d. Anaesthesiology

22. The maximum permissible dose of radiation to the operator of an X-ray machine is

a. 0.05 rem per year

b. 0.5 rem per year

c. 5.0 rem per year

d. 50 rem per year

23. Combined whole body radiation for radiation workers per year is

a. 0.5 rem

b. 5 rem

c. 15 rem

d. 0.1 rem

24. Which of the following substance is most commonly used for protection against X-ray radiation?

a. Zinc

b. Steel

c. Lead

d. Porcelain

25. Badges worn by dental technicians should be changed once in

a. 1 month

b. 3 months

c. 6 months

d. 4 months

26. Among the natural radiation, the one that contributes to more radiation exposure of general population is

a. Terrestrial radiation

b. Cosmic radiation

c. Radon

d. Consumer products

27. Unit of measurement to compare radiation damage is

a. Exposure

b. Effective dose

c. Dose

d. Equivalent dose

28. The most effective method of reducing patients’ somatic exposure while taking radiograph is to use

a. A lead apron

b. Speed E film

c. Additional filtration

d. An open-ended cone

29. Which of the following is the ingredient of the fixing solution of the X-ray?

a. Hydroquinone

b. Elon

c. Sodium bisulphate

d. Acetic acid

30. Crimp marks in a radiograph are due to

a. Droplets of fixing solution

b. Droplets of developing solution

c. Static electricity

d. Sharp bending of the film

15. b

16. c

17. c

18. d

19. a

20. b

21. c

22. c

23. b

24. c

25. a

26. b

27. d

28. b

29. d

30. d

31. Intensifying screens are used in extraoral radiographs to

a. Decrease radiation to patient

b. Increase contrast

c. Decrease contrast

d. Collimation

32. Grid is used to

a. Remove secondary radiation

b. Filter the radiation

c. Remove scattered radiations

d. All of the above

33. Interproximal caries is best detected by which of the following radiographs?

a. Bitewing

b. Periapical

c. Occlusal

d. None of the above

34. Disadvantage of using a grid is

a. Increased patient exposure

b. Decreased exposure time

c. Increased secondary radiation fog to film


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Apr 11, 2016 | Posted by in Orthodontics | Comments Off on II.  Oral radiology
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