Radiographic Interpretation of Dental Caries

multifactorial disease involving complex risk and protective factors; localized destruction of teeth by acid demineralization

dental caries

simultaneous demineralization and remineralization (achieve a balance to prevent caries)

dynamic process of enamel

- metabolic microbial organic acids decrease pH

- dissolution of Ca and PO4

demineralization

- changes in color/glossiness

- cavitation/destruction

- dentin and pulp exposure

3 effects of continuous enamel demineralization

less tissue density, less absorbed by photons (more radiolucent)

How does demineralization present on radiographs?

- occlusal (pits and fissures)

- recurrent/secondary

- facial/lingual (smooth surface)

- root/radicular

- interproximal

5 possible sites for carious lesions

- outer 1/2

- inner 1/2

2 possible progression levels of enamel caries

- outer 1/3

- middle 1/3

- inner 1/3

- directly involving pulp

4 possible progression levels of dentin caries

starts on pits and fissures, hard to detect clinically and radiographically

early stages of occlusal caries

incipient lesions (enamel only), not detected radiographically (superimposition), detected clinically

initial stages of occlusal caries

diffuse radiolucency below enamel occlusal surface (can advance into pulp)

occlusal caries that have lesions into dentin

occlusal caries (into dentin)

What is this an example of?

occlusal caries (into dentin)

What is this an example of?

occlusal caries (into dentin)

What is this an example of?

occlusal caries (into dentin)

What is this an example of?

caries adjacent to margins of restorations

recurrent/secondary caries

diffuse radiolucency below restorations

How do recurrent/secondary caries present on radiographs?

recurrent/secondary caries

What is this an example of?

recurrent/secondary caries

What is this an example of?

recurrent/secondary caries

What is this an example of?

usually close to gingival margin, better seen clinically

facial/lingual (smooth surface) caries

sharply defined round or oval radiolucency

How do facial or lingual caries present on radiographs?

facial/lingual (smooth surface) caries

What is this an example of?

facial/lingual (smooth surface) caries

What is this an example of?

facial/lingual (smooth surface) caries

What is this an example of?

facial/lingual (smooth surface) caries

What is this an example of?

facial/lingual (smooth surface) caries

What is this an example of?

facial/lingual (smooth surface) caries

What is this an example of?

facial/lingual (smooth surface) caries

What is this an example of?

below CEJ, gingival recession

root surface/radicular caries

diffuse radiolucency below CEJ

How do root surface/radicular caries present on radiographs?

root surface/radicular caries

What is this an example of?

root surface/radicular caries

What is this an example of?

root surface/radicular caries

What is this an example of?

root surface/radicular caries

What is this an example of?

NOT carious lesions!

- collar or wedge-shaped radiolucency

- between CEJ and alveolar bone

cervical burnout

cervical burnout

What is this an example of?

cervical burnout

What is this an example of?

arise at or slightly below contact point; viewed a lot better radiographically than clinically

interproximal caries

if dentin is affected, it will appear gray and discolored on marginal ridges

How can interproximal caries be viewed clinically?

irregular radiolucency with base at proximal surface near contact point

How do enamel interproximal caries appear on radiographs?

triangular radiolucency with base at CEJ

How do dentin interproximal caries appear on radiographs?

- bitewings for posterior teeth

- PAs for anterior teeth

What is the best radiographic exam to detect carious lesions?

- controversial results (less detailed compared to intraoral)

- produce ghost images, noise, abnormal configuration of arches

- used for uncooperative patients, severe gag reflex, severe anatomic limitations

3 characteristics of extraoral bitewings

- correct horizontal and vertical angulation

- look at both premolar and molar BWX images (+ PAs for anteriors)

What are important things to remember when viewing bitewings for caries?

usually only seen when large enough to be clinically apparent

How do carious lesions appear on panoramic radiographs?

can show carious lesions at early stages (about 1/2 of proximal surface caries are not seen clinically)

What is the largest contribution for BWX when diagnosing carious lesions radiographically?

25-50% demineralization is needed before visualization (radiographs underestimate actual lesion depth)

What is important to remember about demineralization on radiographs?

- radiographs cannot determine if a lesion is active/cavitated or inactive/arrested

- superficial layers can remineralize

What is important to remember about cavitated lesion progression on radiographs?

- no radiolucency

- initial ultrastructural changes not detectable

E0 carious lesion

- outer 1/2 of enamel

- not cavitated

- may present triangular shape or diffuse radiolucency

E1 carious lesion

- inner 1/2 of enamel

- not cavitated

- may present triangular shape or diffuse radiolucency

E2 carious lesion

- outer 1/3 of dentin

- 33-85% cavitated

- spreads along the DEJ

D1 carious lesion

- middle 1/3 of dentin

- most likely cavitated

- more than halfway to pulp

D2 carious lesion

- inner 1/3 of dentin

- cavitated

- may directly involve pulp (can be called D4)

D3 carious lesion

well-defined radiolucencies on interproximal surfaces

How does radiolucent restorative material appear on radiographs?