Dental Caries

Carious lesions and cervical burnout do resemble each other T/F

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Cervical burnout is found only in the cervical region or tooth neck. T/F

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If the occlusal lesion has not crossed the DEJ, it may not be visible on the radiographic image. T/F

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Occlusal carious lesion is only seen radiographically when it reaches or crosses DEJ as seen in R-3 or R-4 caries. T/F

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When occlusal caries extends into dentin beyond DEJ, detectable radiographic changes include broad-based, RL zone extending into dentin. T/F

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examples of different contrast

careful not to over or under contrast

Enamel interproximal caries (R-1 or R-2) may not be detected radiographically if

if over 1/2 of the enamel is overlapped by adjacent surface

Occlusal Caries Can be classified as:

- incipient / slight (R1) - moderate (R2 & R3) - Severe (R4)

Dental Caries

A pathological process consisting of localized destruction of hard dental tissues by organic acids produced by the microbial deposits adhering to teeth.

Cervical Burn Out RL area

RL limited to interproximal surfaces, below CEJ, outer aspect of tooth often appears intact. CEJs limit areas of cervical burnout incisally or occlusally, and the alveolar crest limits the area apically.

cares Treatment considerations

Reduction in sugar, proper oral hygiene and use of fluorides reduces microbial activity, retards demineralization and promotes remineralization of outermost parts of lesion in non-cavitated lesions. If follow-up radiograph shows progression of lesion, treatment is required. Enamel caries (incipient) requires interceptive treatment but rarely operative treatment. Probability of cavitation is low. Prospect of arresting or reversing the enamel caries is good. Detection of small demineralization in the image requires a decision as to whether this is an active or inactive lesion. Dentinal caries requires treatment.

Cervical Burn Out causes

- Greater density difference between the cervical neck of the tooth & tissues below and above it - Anatomical differences like CEJ, root configurations, & poor horizontal angulation

Occlusal caries shape

- Triangular in shape: apex of lesion is towards the outer surface of the tooth & broad base towards the DEJ. - With advancement, broad-based radiolucency spreads in enamel à into dentin & extends towards the pulp in a spherical pattern. - Irregular shapes of demineralization may be seen. - Margin between carious & noncarious dentin may be diffused.

Cemental or Root Caries causes

- Exposed cementum is soft , usually 20-50 μm thick near CEJ & rapidly degrades. - Cementum is exposed due to gingival recession, loss of interproximal contacts, periodontal disease or poor restorations. - Must be distinguished from cervical burnout.

Classification of caries

-According to location: enamel, dentin (coronal, proximal or interproximal) and cementum (root surface) -According to depth: R 1 - R 4; (incipient to advanced) -Primary or new caries -Recurrent or secondary caries -Rampant caries

Incipient Caries (R-1) - interproximal treatment

-Can be arrested or reversed by remineralization. -Restoration is generally not recommended for R1.

Factors Affecting Caries Interpretation

-Mach banding -Cervical burnout -Other factors

Classification according to location

1) Occlusal 2) Interproximal or proximal 3) Root or Cemental 4) Facial / Lingual (not able specify radiographically)

Occlusal Caries

Most prevalent location • Demineralization more common in children & adolescents on posterior teeth. - Irregular pits and fissures of occlusal surfaces inherently more prone (biofilm)

Cervical burnout and Mach band:

two shadows of doubt in radiologic interpretation of carious lesions HM Berry Jr Cervical burnouts and Mach band effects are effects produced in the retinal receptors and may be seen on images. Cervical burnout: thinner cervical tooth areas produces radiolucent areas that have rounded, diffuse inner borders, but may show intact tooth edges. Mach bands, produced by lateral inhibition of neural receptors in the eye, are optical illusions that may appear in the dentin along the proximal DEJ, or in dentinal peaks bounded by occlusal and proximal enamel. Not every observer has the same ability to perceive Mach bands, and perception is modified by projection, contour, and film and object density.

Mach band effect

• An optical illusion referred to as Mach band effect can produce the caries-like RL in healthy teeth. - It exaggerates the contrast between edges of the different shades of gray

Occlusal Caries detection

• Detection of occlusal R1 (incipient) caries is most effective by direct clinical examination. • Radiographs are not reliable for diagnosis of enamel (R1 & R2) occlusal caries. • If no clinical signs of caries are noted, it would be reasonable to watch or observe these cases and withhold operative treatment.

Caries on Facial / Lingual Surfaces

• Difficult to distinguish surfaces radiographically. • Seen in enamel pits, fissures or small surfaces • Round to semilunar in shape (black hole or RL); often well-defined borders.

Occlusal Caries - early vs later

• Early caries in a pit or fissure is surrounded by dense sound enamel; no early radiographic evidence of caries may be seen. • Later caries spreads along DEJ (into dentin), which may be seen as a RL line between enamel & dentin

dental caries can be found in

• Enamel • Dentin • Cementum / root

Factors Affecting Caries Interpretation

• Following may mimic caries: Mach band effect, cervical burnout and peripheral burnout • Contrast & density: for caries detection short-scale or high Contrast (with lower kVp) is recommended • Underestimation of actual lesion size may occur: • Actual lesion depth if often more

Detection of Dental Caries - radiography as a diagnostic supplement

• In case of lack of cavitation, the demineralization beneath the intact outer surface may be missed clinically. • Clinical access to proximal tooth surfaces is limited; visualized radiographically. • Single radiographs cannot reveal whether the lesion is arrested or active.

Incipient Interproximal caries- R1 radiographs

• Incipient interproximal lesions can be visible on radiographs as RL notch or area on the outer surface of enamel. • Class shape of lesion is a triangle: broad-base of the lesion is at the outer tooth surface and apex is pointed towards the DEJ. May appear as notch, dot or RL band.

Detection of Dental Caries - Intraoral projection

• Intraoral projections are useful for detecting caries (higher resolution). • Diagnostic quality of images is important • Use of proper image receptor and exposure parameters (exp. time, kVp and mA) is important.

Moderate R3 Interproximal caries

• Involves DEJ and demineralization extends into dentin. • Depth: not more than half the thickness of dentin.

Occlusal caries pathology

• Lesion spreads along the enamel rods. • No radiographic change is visible if occlusal lesion is only in enamel. • Once into dentin, the initial detectable radiographic change may be a fine gray shadow (RL line or area) along the DEJ. • Starts often beneath a fissure with little or no change in enamel • Lesion is broad based, bowlshaped, RL zone with diffused margin.

R1 clinical appearance (interproximal)

• Loss of enamel transparency • Chalky-white appearance • Enamel may be roughened or stained due to demineralization • Cavitation follows if untreated

Cervical Burn Out

• Misdiagnosed as caries • RL is seen at the neck of the tooth (just below CEJ) as there is less radiation absorption at the neck of the tooth. • Anterior teeth: RL band across the cervical neck of teeth • Posterior teeth: RL triangular or wedge-shaped area on proximal cervical neck of the tooth

Cervical Burn Out treatment

• No treatment is required. • Often RL disappears if radiograph is retaken with an improved horizontal angulation.

Primary & Recurrent Caries

• Primary: new lesion (no cavity preparation) • Secondary or recurrent lesion - Develops at margins of/or in the vicinity of an existing restoration - May indicate susceptibility to caries, poor oral hygiene, deficient cavity preparation, or a defective restoration - Radiographically, difficult to see in some situations due to existing restoration

Classification of radiographic caries according to depth:

• R-1 = Enamel caries less than 1/2 way through the enamel (incipient caries) • R-2 = Enamel caries at least 1/2 way through the enamel but not involving DEJ • R-3 = Caries through the DEJ but less than 1/2 way to the pulp • R-4 = Caries more than 1/2 way through dentin to the pulp

Interproximal caries radiographic detection - when can we detect it?

• Radiographic detection depends on loss of enough mineralization to result in detectable change in radiographic density. • Loss of small amounts of mineral from incipient lesion may be difficult to detect. • 30% or so demineralization is required to detect on conventional radiograph.

Dental Caries - radiographs

• Radiographs are useful for caries detection as the carious process causes demineralization of tooth structure, which leads to RL zone. • Demineralized area does not absorb as many x-rays as the unaffected area.

Rampant caries

• Severe, rapidly progressing carious destruction of teeth • More observed in children. • Causes: poor dietary habits, frequent sweets, snacks, poor oral hygiene & xerostomia (in adults). • Advanced tooth destruction.

Cemental or Root Caries

• Starts near CEJ; involves both cementum and dentin. Often clinically detected. • Base of the lesion on the outer surface is determined by recession of the gingiva. • Radiographic appearance = defined to diffused inner border, saucer-shaped or scooped-out RL. Absence of root edge.

Incipient (R 1)Interproximal Caries

•Interproximal or proximal: "between 2- adjacent surfaces" •Begins just below the contact point or on outer surface of enamel between the contact point & the height of free gingival margin.

Moderate R2 Interproximal caries

•Involves more than half of the thickness of enamel •Broad-based, diffused RL or

Advanced Occlusal Caries - what sometimes occurs

•Pain: may or may not be present in chronic caries •Long-standing cases may develop sclerotic or reparative dentin between the lesion and the pulp chamber (not always visible). •RO narrow area of increased opacity around the lesion

Severe R4 Interproximal Caries

•Radiolucency penetrates more then half the dentin and may reach the pulp chamber. •Pulp exposure may not be identified from radiographs alone. •Masticatory forces may cause a collapse.

Severe/ Advanced Occlusal Caries

•Readily observed both clinically and radiographically as large cavities or RL in crowns. •Severe lesions spread through dentin, towards the pulp chamber. •Enamel is undermined. •Underlying dentin is carious & masticatory forces cause a collapse & cavitation of occlusal surfaces. •Deeper the lesion = easy detection