Final

Question 1

Cathode Components

Answer 1

(-) tungsten wire filament and molybduim cup *generates electrons

Question 2

Anode Components

Answer 2

(+) tungsten target and copper

Question 3

General Radiation

Answer 3

when electron hits or comes close to nucleus of tungsten atom

Question 4

Characteristic Radiation

Answer 4

when an inner shell e- dislodges. Rare, only above 70kVp, causes ionization

Question 5

Types of Interactions w/ Matter

Answer 5

None (produces image), Photoelectric Effect (x-ray absorbed and collides w inner shell e-,*ionization), Scatter

Question 6

Compton Scatter

Answer 6

x-ray photon collides w/ outer shell e- and ejects it from it’s orbit. *ionization, common

Question 7

Coherent Scatter

Answer 7

low-energy x-ray photon interacts w/ out shell electron altering it’s path *NO ionization, less common

Question 8

Pano Errors

Answer 8

Anterior = skinny; Posterior = fat; Head Turned = further side magnified

Question 9

Exposure Time Equation

Answer 9

1 impulse = 1/60 second

Question 10

kV Peak Rule

Answer 10

increase kVp by 15, decrease exposure time by 1/2.

decrease kVp by 15, double exposure time.

Question 11

Density

Answer 11

(mA) overall darkness of film

Question 12

Contrast

Answer 12

(kVp) how sharply dark/light areas are separated.

high = few shades of grey (low kVp) | low = many shades of grey (high kVp)

Question 13

Required Aluminum Filtration by machine

Answer 13

Above 70 kVp = 2.5mm ; Below 70 kvP = 1.5mm

Question 14

Lead Apron thickness

Answer 14

.25mm by state law

Question 15

Max Permissible Dose of Radiation

Answer 15

Occupational = 50mSv or 5.0rem / year 
Not = 1mSv or .1 rem /year

Question 16

Fixer

Answer 16

hardens emulsion. causes white spots, cutoff = black.

Question 17

Developer

Answer 17

reduction process. causes black spots, cutoff = white.

Question 18

Localization Techniques

Answer 18

SLOB or Right Angle (compare PA + cross sectional image)

Question 19

Film Storage Environment

Answer 19

50-70º, 30-50% humidity

Question 20

Dark Room Environment

Answer 20

70º (temp too high = fogging) | 50-70% humidity (too high = static electricity)

Question 21

Ionization

Answer 21

dislodged electrons interact w/ other atoms causing chemical changes - - produced during: photoelectric effect and compton scatter

Question 22

Free Radical

Answer 22

formed when an x-ray photon breaks up (ionizes) water causing unstable, uncharged atoms. *primary cause for cell damage

Question 23

Stochastic Effects

Answer 23

increasing dose = increasing occurrence of effects. no threshold. ie. cancer, genetic mutations

Question 24

Non Stochastic Effects

Answer 24

large doses cause effects. has threshold. ie. hair loss, erythema, fertility

Question 25

Types of Caries

Answer 25

Incipient (-1/2 thru enamel), Moderate (+1/2 enamel), Advanced (-1/2 dentin), Severe (1/2+ dentin), Root Surface (below CEJ)

Question 26

Resembles Caries

Answer 26

Cervical Burnout, Mach Band (overlapping), Non-metallic Restorations (composite, acrylic), Attrition/Abrasion

Question 27

Perio Disease Stages

Answer 27

1 = <15% coronal root 3rd , 2 = 15-33% , 3 = middle root +

Question 28

Perio Disease Calculation

Answer 28

CEJ to Apex / CEJ to Bone Crest = x / age

Slow = < .23 , Mod = .25-1.0 , Rapid = 1.0 +

Question 29

Pericoronal

Answer 29

pathology noted at crown of impacted tooth

Question 30

Unilocular , corticated

Answer 30

single, roundish, w/ radiopaque border

Question 31

Radiolucent Pathologies

Answer 31

Pulpal Sclerosis/Obliteration, Periapical Granuloma/Abscess

Question 32

Radiopaque Pathologies

Answer 32

Condensing Osteitis, Sclerotic Bone, Hypercementosis, Mandibular Tori

Question 33

Density has a DIRECT relationship with

Answer 33

mA, kVp, time - high density = darker image

Question 34

Contrast + kVp

Answer 34

INVERSE relationship