radiographic of interpretation of dental caries

Radiographic of interpretation of

dental cariesMARAL GHAHREMANI

What are dental caries?

mechanism

Initial carious lesion•Subsurface loss of mineral in the outer tooth surface•Clinical view: opaque ,dark or brownish spot chalky white spot

Use of intra oral radiographs in detecting dental caries

Radiography is a valuable supplement to a thorough clinical examination

the most meticulous clinical examination may fail to reveal demineralization beneath the surface, including occlusal surfaces Clinical access to proximal tooth surfaces in contact is limited.radiographic examination can reveal carious lesions both in occlusal And proximal surfaces that would otherwise remain undetected. The radiograph can not detect if the lesion is active or arrested.

Importance(advantages disadvantages)

Use of intra oral radiographs in detecting dental caries

The lesion is seen in the radiographs as a radiolucent (dark) zone since the demineralized area of the tooth do not absorb as many x-ray photons as the unaffected portion.

Common radiograph of a caries

Use of intra oral radiographs in detecting dental caries

The BW projection is the most useful radiographic examination for detecting caries detecting caries (The use of a film holder with a beam-aiming device reduces the number of overlapping contact points and improves image quality)Periapical radiographs are useful primarily for detecting changes in the periapical bone (use of paralleling technique increases the value of this projection in detecting caries)Traditionally size 2 “adult” films are used for a BW examination from the age of 7-8 years onward

What is Most useful radiographic examination

Viewing conditionsRadiographs used to detect carious lesions should be mounted in frames with dark borders and interpreted using a magnifying glass.

Radiographic detection of lesions –proximal surfaces

typical radiographic appearance:triangle

Susceptible zone MOST COMMONLY is found in the area between the contact point and the free gingival margin.The fact that the lesion does not start below the gingival margin helps distinguish a carious lesion from cervical burnout

False Interpretations (false-positive outcome)

 ABRASION  FROM A CLASP FROM A PARTIAL DENTURE CERVICAL BURNOUT (ARROWS)

False Interpretations (false-positive outcome)

CONCAVITIES PRODUCED BY WEAR  ENAMEL  HYPOPLASIA 

False Interpretations (false-positive outcome)

 MACH BAND EFFECT

False Interpretations (false-Negative outcome)

False interpretations(overlapping contact points)

Lesions with and without Clinical Cavitation

If cavitation has occurred, the lesion will always be active because the bacteria that colonize within the cavity cannot be removed. The presence of cavitation cannot be accurately determined in the diagnostic imageApproximately half of lesions that are just into dentin have surface cavitation,dentinal lesions extending more than halfway to the pulp will most likely be cavitated.Temporarily separating proximal surfaces with orthodontic elastics or springs may allow direct inspection to determine whether there is cavitationAn advanced imaging method, CBCT imaging , is very accurate in determining whether or not a cavity exists in a proximal tooth surface.

Treatment Considerations Enamel lesions non cavitated : no OT needed

caveated : OT neededDentinal lesions whether the lesion has arrested or is progressing(more than half of shallow dentinal lesions can be arrested)

Radiographic detection of lesions –occlusal surfaces

most often occurs in children and adolescents .

The demineralization process originates in enamel pits and fissures.

The lesion spreads along the enamel rods and, if undisturbed, penetrates to the DEJ, where it may be seen as a thin radiolucent line between enamel and dentin.

The classic appearance of lesions extending into the dentin is a broad-based, bowl-shaped, radiolucent zone, often beneath a fissure, with little or no apparent changes in the enamel.

Radiological examination indication: finding discoloring fissures .

If the lesion has not crossed the DEJ, it may not be visible in the image.

Typical appearance

False Interpretations superimposition of the image of the buccal pit with or without an associated carious lesion (positive)Non-metal restoration, which may simulate an occlusal lesion or a deep occlusal fissure.(positive)When an occlusal lesion is confined to enamel, the surrounding enamel often obscures the lesion.(negative)As the lesion extends into the dentin, the margin between the carious and non-carious dentin is diffuse and may obscure the fine radiolucent line at the DEJ.(negative)Mach band (positive)

Cavitation and Treatment Considerations

When the cavitation is visible on clinical inspection, it is usually an indication that the lesion is already well into dentin.Without cavitation, fissure discoloration may indicate the need for radiologic examination A dentinal lesion without clinically apparent cavitation but with a radiolucent extension well into dentin indicates that the carious lesion has passed the DEJ and requires operative treatment.

RAMPANT CARIESSevere, rapidly progressing carious destruction of teethcan be seen in : -children with poor dietary and oral hygiene habits -people with xerostomia Radiographs demonstrate :severe (advanced) tooth destruction, especially of the mandibular anterior teeth.

Radiographic detection of lesions – Buccal and lingual surfaces

often occur in enamel pits and fissures of teeth. small usually round enlarge elliptic or semilunar well defined borders differentiate from occlusal caries

the clinician should look for a uniform non-carious region of enamel surrounding the apparent radiolucency. Clinical evaluation with visual and tactile methods is usually the definitive method to detect buccal or lingual lesions.

overall

Radiographic detection of lesions – Root surfaces

oinvolve both cementum and dentin oare associated with gingival recessionoThe exposed cementum is sensitive to attrition, abrasion, and erosion (rapidly degrades)o most often radiographs are not needed for diagnosis(should e diagnosed clinically ) except In proximal root surfaces.

Differentiation from CERVICAL BURNOUT

by the absence of an image of the root edge and by the appearance of a

diffuse rounded inner border where the tooth substance has been lost.

CARIES ASSOCIATED WITH DENTAL RESTORATIONS

• termed secondary or recurrent caries.

• is most frequently a new primary lesion

faulty shaping or inadequate extension of the restoration

plaque accumulation

•It is important not to confuse secondary or recurrent caries with residual caries.

•A lesion next to a restoration may be obscured by the radiopaque image of the restoration.

•Restorative materials vary in their appearance in the image depending on thickness, density, atomic number, and the x-ray beam energy used to make the image. Some materials can be confused with caries. Older calcium-hydroxide liners without barium, lead, or zinc (added to lend radiopacity) appear radiolucent and may resemble recurrent or residual caries.

•Differentiation: The well-defined margins are useful to  differentiate  from  carious  lesions

Periapical image shows a recurrent carious lesion (arrow)  involving the distal surface of the central incisor in  contact with the radiolucent restoration. Note the  diffuse ill-defined margin of the lesion compared with  the well-defined margin of the restoration. 

THERAPY AFTER RADIATION multiple  carious  lesions  that  occurred after therapeutic radiation exposure. The  lesions start in the region of the cementoenamel  junction.