radiographic of interpretation of dental caries
TRANSCRIPT
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.