Radiography and Caries

Question 1

What is the Role of Radiographs in Caries Detection?

Answer 1

• show mineral loss through decreased density of hard tissue
• revel lesions undetectable by clinical examination

Question 2

What are the 5 Different Types of Radiographs

Answer 2

bitewing
extraoral bitewing
periapical
oblique lateral
panoramic

Question 3

Intra-Oral Bitewing vs Extra-Oral

Answer 3

Intra
- lower dosage
- better resolution
- no or minimal overlap of enamel
- reproducible

Extra
- more comfortable
- better interproximally
- artefacts

Question 4

Why does Demineralisation Appear Darker?

Answer 4

• decreased density
• decreases attenuation
  = less scatter
• area = more radiolucent = darker

Question 5

What are 5 Problems with Radiographs?

Answer 5

• ionising - use must be justified as it damages tissue
• projectional images - lesion may be deeper than it is
  = need 40% mineral loss before lesion shows on radiograph
• artefacts - burn out incisal edge - appear darker
• visual illusion - mach band effect - false shadows
• corrosion products - can hide caries

Question 6

When do you Take Radiographs for High Caries Risk?

Answer 6

posterior bitewing at 6 month intervals until no new lesions

• every year for children

Question 7

When do you Take Radiographs for Moderate Caries Risk?

Answer 7

12 month posterior bitewings

Question 8

When do you Take Radiographs for Low Caries Risk?

Answer 8

children - 12-18th month
adult - 2 years

Question 9

How do you know you have a healthy periodontium?

Answer 9

If the distance between crestal bone margin (alveolar bone) and CEJ is 2-3mm

Question 10

What is Horizontal Bone Loss?

Answer 10

alveolar bone is apical to the normal level

Question 11

What is Vertical Bone Loss?

Answer 11

when there is a significant difference in bone loss at 2 adjacent sides

aka one tooth has more bone loss than the one next to it

= angular defects

Question 12

What does Widening of periodontal space indicate?

Answer 12

mobility

Question 13

How can Calculus Appear?

Answer 13

tiny bumps on teeth

Question 14

What 6 Things May Occlusal Trauma cause?

Answer 14

• marginal widening
• angular defect
• root resorption
• hypercementosis
• root fracture
• sclerosis

Question 15

2 Pros and 3 Cons of Periapicals

Answer 15

High Quality
Reproducibe

• time consuming
• need film holder and paralleling technique
• high dose of radiation