Podcast
Questions and Answers
What is the initial sign of enamel caries observed microscopically?
What is the initial sign of enamel caries observed microscopically?
What happens to the enamel surface during the initial carious process?
What happens to the enamel surface during the initial carious process?
What causes the white appearance of white spot lesions on enamel?
What causes the white appearance of white spot lesions on enamel?
Which conditions allow for the identification of histological zones in enamel caries?
Which conditions allow for the identification of histological zones in enamel caries?
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What indicates that a lesion may have been present for a longer time?
What indicates that a lesion may have been present for a longer time?
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What leads to the demineralization of tooth surfaces in caries?
What leads to the demineralization of tooth surfaces in caries?
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Which of the following best describes one of the outcomes if the pH does not neutralize during the caries process?
Which of the following best describes one of the outcomes if the pH does not neutralize during the caries process?
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Where do microporosities commonly form in enamel caries?
Where do microporosities commonly form in enamel caries?
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What is the primary component that breaks down during the demineralization process in caries?
What is the primary component that breaks down during the demineralization process in caries?
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What is the shape of established enamel caries not extending into dentine?
What is the shape of established enamel caries not extending into dentine?
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What is the purpose of using a clearing agent like quinoline on enamel samples?
What is the purpose of using a clearing agent like quinoline on enamel samples?
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Which zone of destruction in enamel caries is likely the outermost layer affected?
Which zone of destruction in enamel caries is likely the outermost layer affected?
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Which process contributes to the transition from healthy enamel to etched enamel?
Which process contributes to the transition from healthy enamel to etched enamel?
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What type of bacteria are primarily responsible for the formation of caries?
What type of bacteria are primarily responsible for the formation of caries?
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How do air or electrolyte differences in porosities affect light scattering in enamel?
How do air or electrolyte differences in porosities affect light scattering in enamel?
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Which statement is true regarding the histology of enamel caries?
Which statement is true regarding the histology of enamel caries?
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What is the significance of identifying the clinical appearance of enamel caries?
What is the significance of identifying the clinical appearance of enamel caries?
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Which of the following is a key factor in the aetiology of dental caries?
Which of the following is a key factor in the aetiology of dental caries?
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How is the relationship between clinical appearance and histopathology of enamel caries best described?
How is the relationship between clinical appearance and histopathology of enamel caries best described?
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What would be considered the primary preventive measure against caries?
What would be considered the primary preventive measure against caries?
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What is the purpose of the ICDAS scoring system?
What is the purpose of the ICDAS scoring system?
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What does an ICDAS score of 0 indicate?
What does an ICDAS score of 0 indicate?
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Which of the following describes an ICDAS code 1 lesion?
Which of the following describes an ICDAS code 1 lesion?
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What does an ICDAS score of 3 signify?
What does an ICDAS score of 3 signify?
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Why was the ICDAS scoring system developed?
Why was the ICDAS scoring system developed?
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Which ICDAS code is characterized by distinct visual changes in enamel that are visible when both wet and dry?
Which ICDAS code is characterized by distinct visual changes in enamel that are visible when both wet and dry?
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What does prolonged drying reveal in an ICDAS score of 3?
What does prolonged drying reveal in an ICDAS score of 3?
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Which stage of caries corresponds to visible signs after air drying but no evidence when wet?
Which stage of caries corresponds to visible signs after air drying but no evidence when wet?
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What is NOT typically indicated by an ICDAS score of 0?
What is NOT typically indicated by an ICDAS score of 0?
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How does the ICDAS scoring system characterize carious lesions?
How does the ICDAS scoring system characterize carious lesions?
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What is the characteristic mineral content of the surface zone?
What is the characteristic mineral content of the surface zone?
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What is the pore volume range of the body of the lesion?
What is the pore volume range of the body of the lesion?
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How are the dark zone porosities characterized?
How are the dark zone porosities characterized?
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Which zone of the lesion demonstrates initial destruction during carious processes?
Which zone of the lesion demonstrates initial destruction during carious processes?
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What is the pore volume of the dark zone?
What is the pore volume of the dark zone?
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What contributes to the lower pore volume in the surface zone compared to deeper areas?
What contributes to the lower pore volume in the surface zone compared to deeper areas?
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Which features are notable in the body of the lesion when viewed with conventional radiographs?
Which features are notable in the body of the lesion when viewed with conventional radiographs?
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What is the primary characteristic of the translucent zone?
What is the primary characteristic of the translucent zone?
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What role do lipids and proteins play in the dark zone?
What role do lipids and proteins play in the dark zone?
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What happens during the remineralization process in the surface zone?
What happens during the remineralization process in the surface zone?
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Study Notes
Histopathology of Enamel and Dentine Caries
- Histopathology of enamel and dentine caries is a focus of study
- This covers the aetiology and pathogenesis of oral disease, as well as clinical and histological appearances of enamel caries
- Learning outcomes include describing oral diseases and their relevance to prevention, diagnosis and treatment, explaining aetiology and pathogenesis of oral disease, relevant anatomy, and its application to patient management
- A pre-reading lecture on 'Aetiology of Dental Caries' suggests various causative factors (time, plaque bacteria, fermentable carbohydrate, susceptible tooth surface)
- Pre-reading material also includes 'Histology of enamel and dentine' lectures
ICDAS Score
- The International Caries Detection and Assessment System (ICDAS) is a clinical scoring system for diagnosing caries
- ICDAS allows for caries detection throughout different stages and characterises the carious activity of the lesion
- ICDAS was developed for use in clinical research, clinical practice and epidemiological purposes
ICDAS Score- Clinical Appearance in relation to stage
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Score 0: Clinically sound tooth. No caries evidence. No change in appearance, whether when surface is wet or dry
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Score 1: Initial stage caries. No clinical signs of caries when the tooth surface is wet to the touch, but visual signs are evident after drying. White spot and/or brown spots/discolourations are present.
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Score 2: Initial stage caries. Distinct visual changes in enamel. These changes are visible both upon wet and dry surfaces
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Score 3: Moderate stage caries. Localised enamel breakdown without dentine exposure visible when the tooth surface is wet or dry. Prolonged drying of the surface reveals loss of enamel integrity
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The progression of caries is highlighted clinically by the distinct visual changes
Recap on Caries Aetiology
- As the pH of the tooth surface decreases, hydroxyapatite demineralises, breaking down into component ions
- If pH does not neutralise, this demineralization over time leads to caries
- Ca 10 (PO4)6 (OH)2 (hydroxyapatite) breaks down into calcium ions, phosphate ions, and hydroxyl ions
Histological Appearance of Enamel Caries
- Every carious process begins with slight etching of the enamel surface under the dental plaque
- This is reversible
- Under cariogenic circumstances, the tooth dissolves further, resulting in micro porosities in the enamel surface
- These are typically located at prism boundaries
- The first clinical signs are white spots due to a greater portion of incoming light being scattered, compared to surrounding enamel. This happens because mineral is lost from enamel. Air or electrolytes in these porosities have different refractive index which is different from sound enamel
- Where these porosities occur, white spot lesions can incorporate exogenous pigmentation. This makes the lesion appear brown.
- This suggests longer lesion presence
Established Enamel Caries Histology
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Established enamel caries (still within enamel, not extending into dentine) has 4 distinct zones:
- Surface Zone: Relatively unaffected, able to remineralise. Has a relatively high mineral content. Pore volume below 5%.
- Body of the Lesion: Largest area and an area of demineralisation. Pore volume varies from 5-25%. Appears translucent with striae of Retzius well marked
- Dark Zone: Does not transmit light, appears dark under microscopy. Also shows some remineralisation. Pore volume is 2-4%.
- Translucent Zone: Advancing edge of the lesion. Pore volume 1%
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These present as a 'wedge' shaped lesion with the point towards the dentine in smooth surface caries, and towards the enamel surface in pit and fissure caries
Identifying Histological Zones
- Samples are cleared using a clearing agent (quinoline) which has identical refractive index to enamel to ensure correct identification of all zones.
- Classical zones of enamel caries are identified due to differences in the amount and size of porosities. Transmission light microscopy is used
- Different clearing mediums and polarised light microscopy allow for measurement of pore size and volume.
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Description
This quiz focuses on the histopathology of enamel and dentine caries, exploring the aetiology and pathogenesis of oral diseases. You will delve into clinical and histological appearances, prevention, diagnosis, and treatment methods related to caries. The quiz also incorporates the International Caries Detection and Assessment System (ICDAS) for caries assessment.
