caries interpretation

what is part of the caries assessment

• pt history

• clinical exam

• radiographic exam

review of GV black classification

radiographs are most helpful for detecting which type of caries:

C I

CII and III

C IV

C V

CVI

CII and III (II more important)

_________can help identify CIII caries earlier

transillumination

what is the caries process and how it will eventually appear in a radiograph

demineralization → destruction → dec in density → greater x-ray penetration in carious area → radiolucency

rank PANO, CBCT, BWX, and PAs in order from highest to lowest spatial resolution

1. BWX

2. PAs

3. PANOs

4. CBCT

what is the role of BWX

to detect small interproximal caries before they can generate symptoms or become clinically visible

how should PANO be used in caries detection

• caries that are visible are often large enough to be clinically apparent

• should NOT rely to detect caries

how should CBCT be used in caried detection

• should equivalent detection compared to intraoral modalities for NON-RESTORED teeth

• should NOT use CBCT to solely detect caries

why should CBCT NOT be used for routine method of caries detection

• beam-hardening and streak artifacts from metal objects are a limiting factor

• inc pt dose

• inc pt cost

what should be included in your radiographic evaluation

• location- tooth and surfaces

• depth- extent toward pulp

• primary vs recurrent caries

what are primary caries

caries on an unrestored tooth surface

what are secondary caries

caries associated w an existing restoration

what are the classification systems of caries

• international caries classification and management system (ICCMS)

• international caries detection and assessment system (ICDAS)

• ADA caries classfication system

what are the four radiographic stages of the merged ICDAS/ICCMS

• sound surfaces- code 0

• initial stage caries- RA

• moderate stage caries- RB

• extensive stage caries- RC

merged ICDAS/ICCMS code 0

no radiolucency

merged ICDAS/ICCMS RA

• outer half of enamel- RA1

• inner half of enamel w or w/o DEJ involvement- RA2

• outer third of dentin- RA3

merged ICDAS/ICCMS RB

middle third of dentin RB4

merged ICDAS/ICCMS RC

• inner third of dentin- RC5

• reaches the pulp- RC6

we can reliably predict when tooth surface is cavitated and dentin is heavily infected when radiographic penetration is deeper than…

the outer 1/3 of dentin

___% of radiographic lesions that extended into the outer third of dentin show cavitation

32%

___% of lesions extending into the middle third of dentin or deeper were cavitated

72%

merged ICDAS/ICCMS categories

• sound- 0

• initial- A

• moderate- B

• extensive- RC

what are the stages of the ADA caries classification

• sound

• initial

• moderate

• advanced

according to the ADA caries classification system, what is E1

outer ½ of enamel

according to the ADA caries classification system, what is E2

inner ½ enamel

according to the ADA caries classification system, what is D1

to outer 1/3 dentin

according to the ADA caries classification system, what is D2

to middle 1/3 of dentin

according to the ADA caries classification system, what is D3

inner 1/3 of dentin

classify this according to radiographic presentation of the ADA

E1

classify this according to radiographic presentation of the ADA

E2

classify this according to radiographic presentation of the ADA

D1

classify this according to radiographic presentation of the ADA

D2

classify this according to radiographic presentation of the ADA

D3

classify this lesion according to the ADA and ICDAS/ICCMS systems

caries within the outer half of the enamel: RA1, E1

classify this lesion according to the ADA and ICDAS/ICCMS systems

caries within the inner half of the enamel: RA1, E1

classify this lesion according to the ADA and ICDAS/ICCMS systems

caries within the outer 1/3 of the dentin: RA3, D1

classify this lesion according to the ADA and ICDAS/ICCMS systems

caries within the middle 1/3 of dentin: RB4, D2

classify this lesion according to the ADA and ICDAS/ICCMS systems

caries within the inner 1/3 of the dentin: RC5, D3

classify this lesion according to the ADA and ICDAS/ICCMS systems

caries in contact w pulp: RC6, D3

the decision to tx carious lesions surgically is based on what 3 things:

• caries risk status of pt

• depth of lesion

• whether there is cavitation

when is conservative intervention indicated, be specific

when there is only involvement or the enamel or outer 1/3 of dentin- controversy

when is surgical management indicated, be specific

when the cavitation or lesion has reached the middle third of the dentin

difference in management is mostly based on … give an ex

caries risk status; higher risk would benefit from more proactive approach

when decision is made to NOT manage the lesion surgically, what should be done to ensure proper monitoring of the lesion

• follow-up period based on pts caries risk

• new images should be as similar as possible for accurate comparison to see any progression

what is the susceptible zone

in proximal caries, is between the contact point of the teeth and gingival margins

what are incipient caries

caries DO NOT extend to DEJ; most often defined at extending ½ through enamel

what is the shape of incipient proximal caries

triangle w broad base at outer surface

why are incipient caries the shape that they are

demineralization occurs along long axes of enamel rods- oriented 90 degrees to enamel surface

what are primary caries

involves DEJ or extends through

what happens to the shape of primary caries once it reaches the DEJ

triangular shape gets lost, lesion gets bigger due to curvilinear or “s-shaped” arrangement of dentin tubules

top arrow, classify this lesion based on the ADA caries classification system

D1

bottom arrow, classify this lesion based on the ADA caries classification system

D2

classify this lesion based on the ADA caries classification system

D3

why is it important to monitor caries in primary dentition

• primary teeth have thinner enamel

• dentin is reached more quickly

• more rapid progression of caries

how can occlusal caries be read in radiographs

• large lesions are easily observed

• not very effective at detecting small lesions- nearly impossible to identify enamel-only lesions

what shape are occlusal lesions if they can be seen in a radiograph

thin line, triangle, or cup-shaped zone under enamel w base at DEJ

what type of radiograph would it be easier to identify occlusal caries; why

PANO- angle of the beam

why is the clinical exam important when identifying occlusal caries

high false negative rate in 2D radiographs

where do buccal and lingual caries typically arise

in cervical region, pits, or fissures

how do buccal and lingual caries show up in a radiograph

well-defined ovoid radiolucency

buccal/lingual caries may often be confused w occlusal caries due to superimposition, how can you sort of differentiate them

occlusal usually not as well-defined (pic shows B/L caries)

how can you tell solely based on the radiograph whether the pt has a buccal or lingual caries

SLOB rule!!

where do root caries typically arise

pt w gingival recession and/or bone loss, on B/L/proximal root surfaces of teeth involving cementum

shape of root caries on radiographs

saucer like irregular cavitation

root caries on radiographs can often be confused w…

cervical burnout

what are rampant caries

rapid progression w severe widespread involvement

would group of people are rampant caries most often seen in

• young children- poor hygiene and dietary habits

• pts w xerostomia- often secondary to head/neck radiation therapy

what are radiation caries

seen on surfaces and teeth that do not usually present carious- often cervical location

how can secondary/recurrent caries occur

can be caused by defective restoration and/or ineffective hygiene

what is the best imaging modality to use for recurrent/secondary caries, and why

BWX due to beam angulation

what are residual caries

represent areas of demineralization that remain when the original lesion has not completely removed

old composite restorations can look radiolucent on radiographs, how can you tell the difference between the restoration and recurrent caries

composite will be well-defined, caries are more diffused

what are limitations and pitfalls of 2D radiographs

• false positives

  • cervical burnout

  • mach band affect

• radiographic vs clinical depth

• caries activity impact of angulation and superimposition

what are false positives

when a carious lesion is thought to be detected on image but tooth structure is actually intact

what is the most common source of false-positives

misinterpretation of cervical burnout

what is cervical burnout

artifact that can mimic caries commonly at or just apical to CEJ near alveolar crest

what is the cause of cervical burnout

x-rays passing tangentially through proximal area encounter less structure; shallow depression/concavity on M/D root surface can make area appear more radiolucent

when thinking of cervical burnout, thinner tooth structures absorbs fewer x-rays, so it will appear more ________________ (radiopaque/radiolucent) on the radiograph

radiolucent

caries or cervical burn out

burnout

caries or cervical burnout

caries

what is the mach band effect

artifact caused by differential contrast between more opaque enamel and less opaque dentin → results in perception of a radiolucent band in the superficial dentin adjacent to DEJ

what causes the mach band effect

• optical illusion from differential stimulation and inhibition of neighboring receptors into retina

• retinal receptors overstimulated by enamel opacity inhibit adjacent receptors that perceive more radiolucent dentin

how can you overcome the mach-band effect

• mask the more radiopaque enamel

• if the radiolucent band disappears, not caries

• if continues to be seen, caries

how can depth be a limitation to radiographic caries detection

• caries are further advanced clinically than radiographs indicate

why can you not trust x-rays when evaluating the depth of the lesion

bacterial penetration of dentinal tubules and early demineralization do not produce enough change in density to affect x-ray attenuation

it is estimated that enamel demineralization must be _______% before a lesion can be observed on an image

>~35%

demineralization detected on an image does not equate to ________ carious lesions

active (can represent older, inactive/arrested lesion)

how is remineralization possible in early lesions

due to contact w calcium and phosphorus in saliva

what is required to differentiate active from arrested caries

a second image

the degree of radiolucency determined by the caries extent in what direction

the buccolingual plane

how is superimposition a limitation of 2D imaging

• caries depth relative to the pulp; may appear the pulp is involved when it is not

• tooth w a broad contact does NOT show caries as well as a greater density tooth structure surround caries

how is horizontal angulation a limitation of 2D imaging

change in angulation impacts ability to detect and stage carious lesions

what is horizontal angulation

• contact overlap can obscure lesion and DEJ

• changes of lesions relative to other structures→ DEJ and pulp

why is too much vertical angulation not a good thing

if looking at restorations particularly, if the angle is big → decay will be hidden under restoration

what should be on your differential dx for radiographs for detecting caries

• unfilled cavity restoration

• radiolucent restorations

• cervical burnout

• mach band effect

• idiopatchis cervical resoprtion

• dental anaomalies

• tooth wear abfraction

can cervical burnout extend below the level of the bone

no, only caries

what is idiopathic cervical resorption

type of external resorption

describe how tooth wear can be seen in a radiograph

physiologic (attrition) or non-physiologic (abrasion/erosion) wear will result in low-density areas that may mimic caries

what is an abfraction

non-carious cervical lesions