BW radiograph

Question 1

indications for BW

Answer 1

1. identify caries and monitor progress of caries
2. periodontal status
3. existing restorations, crowns and bridges

Question 2

ideal positioning for BW

Answer 2

chchvr
1. contact: teeth and receptor in contact
2. central: receptor centrally positioned in holder
3. horizontal plane: beam meets teeth and receptor
4. horizontal angulation: alignment of receptor parallel to tangent of arch
5. vertical plane: beam 5-8 deg to compensate curve of monson
6. reproducible

Question 3

premolar BW placement

Answer 3

include 3d

Question 4

molar bw placement

Answer 4

2mm distal of most posteriorly erupted tooth

Question 5

technique for bw
- black in…
- dot …
- whole… in hole
- cotton roll?

Answer 5

• black in sight (not numbers)
• dot on top (BW), dot in slot (PA)
• whole film in hole
• no cotton roll (unlike PA can put cotton roll between bite block and teeth

Question 6

advantage of bw w holder

Answer 6

• simple
• holder: auto horizontal and vertical angulation
• no cone cut

Question 7

disadvantage of bw w holder

Answer 7

• not for children
• uncomfortable

Question 8

advantage of bw w tab

Answer 8

• for children
• inexpensive, simple

Question 9

disadvantage of bw w tab

Answer 9

• cone cut
• non reproducible image
• horizontal and vertical angulation determined by technician
• tongue easily displace receptor

Question 10

criteria for BW

Answer 10

1. appropriate density nad contrast
2. include 3d and 7 –> if 8 erupted, include 7-8 contact
3. occlusal plane in the middle
4. alveolar crest of max and mand
5. no cone cut
6. no artefacts
7. no overlap of proximal surfaces
8. no image distortion/blur

Question 11

common imaging errors for BW

Answer 11

1. cotton roll
2. no biting on bite block
3. horiztonal angulation (overlaps of proximal sirface) and vertical angulation (occlusal plane not in middle)