Radiographic Diagnosis of

Dental Caries

Caries

Bitewing Film primarily

Periapical film also used

Low kVp, high contrast

(short scale)

Approximately 50 % demineralization is required for radiographic detection of a lesion.

The thickness of the tooth buccolingually masks the carious lesion when it is small.

The actual depth of penetration of a carious lesion is deeper clinically than radiographically.

Proximal caries susceptible zone

caries

Factors affecting caries diagnosis:

Buccolingual thickness of tooth

Two-dimensional film

X-ray beam angle

Exposure factors

Radiographic Caries

I

M = Moderate I = Incipient

A = AdvancedS = Severe

S

AMA

IncipientInterproximalCaries I

Up to half the thickness of enamel

Cone-shaped radiolucent area

Treat or no treat ?

Usually not restored:* Unless patient has high caries activity

IncipientInterproximalCaries

I

Incipient

ModerateInterproximalCaries M

More than half-way through the enamel (up to DEJ)

Moderate

AdvancedInterproximalCaries AA

From DEJ to half-way through the dentin

Advanced

Advanced

Advanced

Advanced

IncipientModerateAdvanced

SevereInterproximalCaries

More than halfway through the dentin

S

Severe

Anterior interproximal caries can usually be diagnosed by directing bright light through the contact areas.

Transillumination

Must have penetrated into dentin

Diagnosed from clinical exam

Radiographs are not a reliable diagnostic aid for the detection of occlusal caries.

Occlusal Caries

The apex of the triangle is toward the outer surface of the tooth and the base is at the dentino-enamel juncition.

Occlusal Caries

Occlusal

Occlusal

Use clinical exam

Can’t determine depth

Appears as round dots

Buccal/Lingual Caries

Buccal/lingual

Older patients with recession or periodontitis

Root Caries

Root caries

Root caries

Cervical burnout appears as a Cervical burnout appears as a collar or wedge-shaped radiolucency on the collar or wedge-shaped radiolucency on the mesial and distal root surfaces near the CEJ of a toothmesial and distal root surfaces near the CEJ of a tooth. .     The tissue density at the cervical region of the tooth is less than the regions The tissue density at the cervical region of the tooth is less than the regions above and below it. (variable penetration of X-ray)above and below it. (variable penetration of X-ray)

Burn-Out:Burn-Out:*Mainly located at the neck of the tooth (Demarcated above *Mainly located at the neck of the tooth (Demarcated above by enamel cap or restoration and below by the alveolar by enamel cap or restoration and below by the alveolar bone)bone)**Usually all teeth are affected esp. smaller premolars.**Usually all teeth are affected esp. smaller premolars.***it is more obvious when the exposure factors are ***it is more obvious when the exposure factors are increased!increased!

Root caries may be confused with cervical burnout

Radiolucency seen above left (arrow) disappears on periapical film of same tooth (above right).

Cervical burnout

Anterior Cervical Burnout

bone level

cervical burnout area

Cervical burnout in the anterior region due to gap between enamel (red arrows) and alveolar bone over root.

May be due to high caries rate, poor oral hygiene, failure to remove all the caries, defective restoration or a combination.

Recurrent Caries

Is not always easy to detect radiographically:

1.Location of caries lesion relative to restoration.

2.Angulation of X-ray beam.

Recurrent Caries

Recurrent caries(red arrows)

Recurrent caries

Recurrent caries

Rampant Caries

* Usually found in children and teens with poor diet and inadequate oral hygiene.* Patients with xerostomia

Found in head/neck radiation therapy patients with xerostomia

Fluoride used for control

Radiation Caries

Before radiation

1 year after radiation

Mach BandOptical illusion giving appearance of increased radiolucency at junction of differing tissue densities

Periodontal Disease

Periodontal ligament attachment and alveolar bony support of the tooth have been lost.

Junctional epithelium migrates apical to the CEJ.

Bitewings best for diagnosis. Some feel that paralleling PA’s are best.

Higher kVp recommended (long scale, low contrast).

Compare images from differentvisits (using same technique).

Periodontal Disease

• Two-dimensional representation of a 3-D anatomic structure.

• Superimposition of the bone and tooth structures

* Relationship of hard to soft tissues not evident

Limitation of Radiographs

* Presence or absence of periodontal pockets.

* Early bone loss (<3mm) is not evident.

* Early furcation involvement is not evident.

Limitation of Radiographs

* PA: X-ray beam alignment will obliterate the presence of extent of furcation involvement.

* Facial and lingual aspects of alveolar bone will be superimposed over the furcation.

Limitation of Radiographs

Early radiographic changes:

1.Crestal irregularities.2.Triangulation3.Interdental septal bone changes

Benefits

Involvement:

LocalizedGeneralized

Periodontitis

Periodontitis

Normal Anatomy:

Alveolar crest corticated

1-1.5 mm from crest to CEJ

Parallel to line between CEJ’s

Crest is pointed anteriorly

Corticated alveolar crests

1-1.5 mm

CEJ

Alveolar crests morepointed anteriorly

Contributing Factors• Occlusal trauma• Open contacts• Overhangs, poor contours• Calculus• Post-extraction defects• Systemic involvement (diabetes, blood disorders, hormonal changes, stress, AIDS)

Horizontal bone loss: Parallel to line drawn between adjacent CEJ’s

Vertical (Angular) bone loss: More bone destruction on interproximal aspect of one tooth than on the adjacent tooth

Gingivitis

No bone loss

No radiographic signs

Mild Adult Periodontitis

Loss of cortical density

Rounding off of junction between alveolar crest and lamina dura

Blunting of crest anteriorly

Mild adult periodontitis

Horizontal bone loss or vertical osseous defects

Total extent of bone loss not evident

May have slight mobility

Moderate Adult Periodontitis

Moderate adult periodontitis(red arrows point to calculus)

Moderate adult periodontitis

Severe Adult Periodontitis

Tooth mobility

Extensive horizontal bone loss or vertical osseousdefects

Furcation involvement

Severe adult periodontitis

Severe adult periodontitis

Severe adult periodontitis

Radiopaque: Structures with higher object density, such as amalgam, gold, silver points, pins, gutta percha, porcelain.

Radiolucent: Structures with lower object density, such as older composites and bonding agents.

Restorative Materials

Gold crowns, amalgams

Retention pins

porcelain crowns

Ceramic Crowns

crownamalgam

crown

silver pointsgutta percha

cast post

Red arrows point to basesGreen arrow indicates recurrent caries with fractured restoration

Compositesold new