Caries Detection Methods Flashcards
What kind of process are dental caries?
A dynamic process between demineralization and remineralization.
Health is not the absence of disease (caries are not the presence/absence of cavities)
What are the principles of identifying carious lesions?
Detect dental caries at its earliest stage possible.
Provide valid prospective caries risk assessents for different age groups
Determine present caries activity and monitor lesions behaviour over time.
What are the features of the ideal diagnostic tool?
Accuracy
Reliability
Precise/simple
Easy to apply
Useful for all surfaces of teeth
Identifying caries adjacent to restorations
Objectivity
Sensitivity
Specificity
Reproducability
Validity
What are the diagnostic methods used for dental caries?
Digital radiography
Digital image enhancement
Digital subtraction radiography
Tuned-aperture computed tomography
Visible light
Optical caries monitor
Digital imaging fiber-optic transillumination
Quantitative light/laser-induced fluorescence
Laser light diagnodent
Diagnodent pen
Electric current Electrical conductance measurement
Electrical impedence measurement
US caries detector
How are carious lesions explored? Is this the recommended way to diagnose dental caries?
An area is carious when the explorer ‘catches’ or resists removal after the insertion into a pit or fissure with moderate to firm pressure and when accompanied by one or more of the following signs of caries:
A softness at the base of the area
Opacity adjacent to the pit or the fissure
Softened enamel adjacent to the pit or fissure.
THIS IS NOT RECOMMENDED
How does fiber-optic transillumination work?
Snell’s law
Refraction of light through varying media
Useful for detection of cracks, restorations, enamel defects, and caries.
What is a white spot lesion?
An early carious lesion where loss of mineralized layer creates porosities that change the refractive index of usually translucent enamel.
ICDAS 1 - 2 lesions.
What is digitalimaging fiber-optic transillumination?
Combines FOTI with digital CCD -> Computer analysis
What are the types of results that can arise from fluorescence induced fiber optic transillumination?
Use of fluorescence in caries detection
Heterogeneous emission spectral bands in the carious region compared to the sound surface of the tooth
Intraoral camera that illuminates the tooth with light in the violet-blue wavelength (290 - 450 nm) and captures fluorescence above 520 nm.
Sound areas of the tooth fluoresce green
What is laser fluorescence used for?
Early diagnosis of the dental caries
Useful for early detection of hidden caries in non-cavitated teeth
Emite infrared light light (655nm) that can be absorbed by organic and inorganic tooth materials, and the process of remitted fluorescence shows various scales between 0 and 99.
What do readings on laser fluorescence tell us?
0 to 15 - no active caries
16 to 30 - preventative or operative care with caries risk assessment and recall intervals.
31 to 99 - operative care recommended
What are the limitations of using laser fluorescence?
High chance of false positives:
Surface must be dry and clean before reading is made
Influenced by stain, plaque, calculus, and margins of restorations
Recommended to be used with other modalities
What are occult/hidden caries?
Occlusal caries which is not diagnosed clinically because the occlusal surface looks ostensibly intact and radiographs show radiolucencies in dentin.
What are occult/hidden caries?
Reported prevalence of 2 - 50%
What causes occult/hidden caries?
Aetiology is unclear but appears to be a pre-eruptive process (due to pre-eruptive intracoronal resorption)
Post-eruptive processes (Fissure caries)
What is electrical conductance based on?
The principle that a demineralized tooth has more pores filled with water or saliva and this is more conductive than intact tooth surface.
What is electrical impedence measurement based on?
A measure of degree at which an electric circuit resists electric current flow when a voltage is applied across 2 electrodes.
Carious tissue has lower impedence than sound tooth.
What is the advantage of ECM over Electrical impedence?
As different dental structures have different molecular composition and hence respond to electrical currents of differing frequencies.
What are the advantages and disadvantages of electrical systems for diagnosis of dental caries?
Advantages:
Quantification of data helps to minimize human errors
Allows for reproducibility and recording of data for future followups or to track progress of caries
Allows for the detection of non-cavitated lesions
Minimally intrusive technique
Disadvantages:
Low specificity (low chance of negative test among patients without disease)
Lower efficiency in surface specific measurements
Background resonance may lead to cardiac disorders. Minimm frequency do not fall below 100Hz so as not to
How does ultrasound work?
Frequency of >20000Hz and have all the properties of waves, in that they may be reflected, scattered, refracted, or absorbed.
Amount of sound reflected gives information about the structure of reflecting interface
Sound waves reach the tooth via a probe and a coupling medium
What kind of disease are caries?
Caries are a biofilm bacterial disease.
A thick EPS biofilm with acid-producing bacteria.
Diet and lifestyle grow the EPS. Frequency of sugar exposure and acid exposure.
Low pH grows more acid producing bacteria and acid dissolves enamel causing a carious lesion to form.
How should caries be viewed as a disease? How should they instead be treated?
It is multifactorial, lesions are the outcome of the disease not the cause and so addressing the cause is vital
Restorations don’t stop the disease and instead we must analyse the causes of the disease.
How does thickness of plaque affect chance of disease?
Thickness of plaque is a key factor in oral disease and double thickness plaque are most likely to cause development of carious lesions.
How does lesion location affect diagnosis and treatment of dental caries?
Each location presents different diagnostic challenges due to anatomical differences and the effect that has overall.
How can smooth surface lesions be detected and treated?
Gently air-dry tooth surface showing the extent of early white spot lesions.
Smooth surface lesions can be remineralised by plaque control and CPP-ACP.
What are smooth surface caries?
Caries that are not cavitated yet. Just a simple acid decalcification.
What kind of cavitation should be treated?
Intact surface if active can be arrested or reversed (via remineralization) this can be monitored with radiographs.
Cavitated surface must be restored. (if cavitated or in deep dentine)
What are radiographs good for detecting?
Research shows that radiographs are very good at detecting the extent and degree of proximal radiolucency but not very good at determining proximal cavitation.
Why should explorer not be used for detecting fissure caries?
It causes iatrogenic damage.
How easy is detection of occlusal caries with x-rays?
Not very good. They lack sensitivity for occlusal caries.
Deep occlusal cavities can be detected with radiographs.
How should fissure caries be investigated?
Using vision (ideally magnified with loupes and good illumination + dry field.
No radiographs, no dental explorers.
What are the benefits of using magnification + illumination + drying?
Shows occlusal demineralisation areas
91.2% of occlusal microcavities associated with a white spot lesion have progressed into dentine and must be restored.
How does fluorescence work?
The principle of fluorescence is that input of one wavelength of light causes the tooth to emit light at longer wavelengths. This gives us information about structure that is fluorescing.
How accurate was durr vistaproof found to be?
Has a specificity of 85.7% and a sensitivity of 92.3%
Easier to use than diagnodent.
How does diagnodent work?
Uses a red diode.
We can now detect and quantify occlusal dentine caries and does not detect mineral loss
It works by fluorescing the breakdown product of bacteria called fluorophores particularly protoporphyrin-IX
What kind of device is diagnodent?
Wireless
Small
Handy
Easy to use
Portable
What are the limitations of diagnodent?
Has poor sensitivity creating false readings.
Anything in or above the fissure can fluoresce and cause high false readings
A thin black/brown stain can fluoresce
What can diagnodent confidently tell us?
Not to intervene when there are low readings.
