Radiographic diagnosis of caries Flashcards
What is caries?
Multifactorial, infectious disease. Lactic acid causes demineralisation and demineralisation may extend well into dentine before cavitation occurs.
How do we describe lesions?
Enamel, dentine, root, primary, secondary/recurrent, residual - demineralised tissue left behind when a filling is placed.
Active - progressing demineralisation
Early childhood - children under 6
Rampant - adolescents
Arrested/inactive - remineralisation process
How do we classify caries?
Class I: Pit or fissure
Class 2: Interproximal surface of posterior teeth
Class 3: Interproximal area of anterior teeth
Class 4: Interproximal area of anterior tooth involving incisal edge
Class 5: Lesion affecting cervical third of tooth
What is the pitts classification of caries?
D1: white/opaque/brown lesion: surface hard on probing
D2: slight loss of surface, sticky fissures, no dentine involvement
PREVENTATION FOR ABOVE
D3: Dentine involvement not pulp
D4: Possible or definite pulpal involvement
RESTORATIVE
What is fibreoptic transillumination?
White light shone into contact points through probe, normal tooth scatters light caries reduces spread of light so appears dark - observed clinically.
Best for detection of approximal caries
Restoration blocks spread of light
What is fluorescence?
Light of known wavelength scatters through material some waves are absorbed and some lose energy and are emitted as waves with longer wavelength.
Changes with density - caries has a low density so alters fluorescence.
What are bitewing radiographs?
Most useful as maximum coverage for the lowest dose
Should see mesial contact point of first premolar to the most distal contact point
In adults, may need two to see all contact points
What is the acceptable amount of enamel overlap on radiographs?
No or minimal overlap but up to half thickness of enamel acceptable
What is a periapical radiograph?
Shows fewer crowns but has similar dose to bitewing
What is an oblique lateral radiograph?
Extraoral image with lower resolution than bitewing but useful for non tolerating children
Are panoramic radiographs indicated for caries?
No but used if a patient cannot tolerate intraorals, but has a lower resolution and as it moves it is not as sensitive and can contain artifacts so not useful for diagnosis of caries.
What are the advantages of an extraoral bitewing in a panoramic machine?
More comfortable, better interproximal separation between contacts than a panoramic.
50% dose reduction
What are the disadvantages of an extraoral bitewing in a panoramic machine?
Higher dose than bitewing, lower resolution and less reproducible.
How much mineral loss has to happen before a radiograph can detect it?
40%
What are the benefits of taking a radiograph?
Can reveal undetectable lesions by clinical exam - pre cavitation and approximal surfaces.