Histopathology of Dentine Caries
42 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What occurs when the pH of the oral environment lowers significantly?

  • Tooth surface undergoes demineralization (correct)
  • Tooth enamel strengthens
  • Teeth remineralize automatically
  • Plaque bacteria become inactive

    • Which of the following statements best describes the aetiology of dental caries?

  • The interaction of plaque bacteria and fermentable carbohydrates leads to caries. (correct)
  • Caries result solely from physical damage to the tooth.
  • Caries develop exclusively from genetic factors.
  • Caries are caused only by poor oral hygiene.

    • Which zones of destruction are mentioned in the context of dentine caries?

  • Surface zone, Body of caries, Zone of penetration, Zone of necrosis (correct)
  • Inner zone, Outer zone, Carious zone, Reversal zone
  • Epidermal zone, Dermal zone, Cartilaginous zone, Mesenchymal zone
  • Enamel zone, Dentine zone, Pulp zone, Necrotic zone

    • What is the clinical appearance characteristic of dentine caries?

    <p>Discoloration and softening of dentine</p> Signup and view all the answers

    How does dentine protect itself from caries?

    <p>Through the production of reparative dentine</p> Signup and view all the answers

    Which dental condition is associated with the breakdown of hydroxyapatite due to acid action?

    <p>Dental caries</p> Signup and view all the answers

    What does a successful prevention strategy for caries require?

    <p>A balance of dietary habits and oral hygiene practices</p> Signup and view all the answers

    What is the primary cause of dental caries development in the mouth?

    <p>Accumulation of plaque bacteria on tooth surfaces</p> Signup and view all the answers

    What is the primary purpose of the ICDAS scoring system?

    <p>To diagnose caries and assess carious activity</p> Signup and view all the answers

    Which code corresponds to moderate stage caries characterized by a dark shadow from dentine?

    <p>Code 4</p> Signup and view all the answers

    What type of cavity is indicated by an ICDAS score of 6?

    <p>An extensive cavity that has extended into dentine</p> Signup and view all the answers

    What is a significant characteristic of extensive stage caries classified under Code 5?

    <p>It shows visible evidence of demineralization</p> Signup and view all the answers

    Which component of dentine is primarily responsible for its organic structure?

    <p>Collagen</p> Signup and view all the answers

    What does the term 'dentinal-pulp complex' refer to?

    <p>The intimate relationship between dentine and the dental pulp</p> Signup and view all the answers

    What does the ICDAS scoring system enable regarding caries detection?

    <p>Identifies the caries process at various stages</p> Signup and view all the answers

    Which of the following best describes a common limitation of the ICDAS system?

    <p>It has a subjective element in caries diagnosis</p> Signup and view all the answers

    Which caries stage is characterized by a distinct cavity visible in opaque or discolored enamel?

    <p>Extensive Stage</p> Signup and view all the answers

    How does the mineral component of dentine primarily exist?

    <p>As hydroxyapatite</p> Signup and view all the answers

    What characterizes Zone 3, the Zone of Demineralisation?

    <p>It consists of firm demineralised dentine that does not require removal.</p> Signup and view all the answers

    Which statement is true regarding Zone 4, the Translucent (Sclerotic) Zone?

    <p>It represents hyper-mineralised tubules aiming to protect the pulp.</p> Signup and view all the answers

    What is the nature of Tertiary Dentine in relation to the lesion?

    <p>It is deposited at the pulp-dentine border as a protective measure.</p> Signup and view all the answers

    How does Reactionary Dentine differ from Reparative Dentine?

    <p>Reparative Dentine originates from a strong irritant, while Reactionary Dentine comes from a mild irritant.</p> Signup and view all the answers

    What is the visual characteristic of Zone 4 when viewed radiographically?

    <p>It is typically a whiter area indicating hyper-mineralisation.</p> Signup and view all the answers

    What is the main characteristic of macroscopic dentine caries classified as ICDAS Code 4?

    <p>Presence of heavy grey shadowing</p> Signup and view all the answers

    What happens to the dentine hardness as bacterial destruction progresses in ICDAS Codes 5 and 6?

    <p>Dentine softens and becomes easier to excavate</p> Signup and view all the answers

    Why is it not advisable to use a sharp probe on the cavity floor in advanced caries?

    <p>It can cause further damage to healthy tissue</p> Signup and view all the answers

    How does the macroscopic appearance of dentine caries correlate with its histological appearance?

    <p>Macroscopic caries show a mushroom shape while progressing</p> Signup and view all the answers

    What is indicated by the heavy infection of dentine during caries progression?

    <p>A need for immediate restoration</p> Signup and view all the answers

    As caries progresses, what happens to the integrity of the crown?

    <p>It becomes compromised due to enamel breakdown</p> Signup and view all the answers

    The lateral spread of caries under the enamel is primarily due to which of the following?

    <p>Change in the hardness of the substrate</p> Signup and view all the answers

    What is the primary visual indicator of ICDAS Code 5 caries?

    <p>Noticeable dentine exposure</p> Signup and view all the answers

    How do dentine caries in their advanced stages typically appear when excavated?

    <p>Hard and brownish</p> Signup and view all the answers

    What can be observed at the junction of the enamel and dentine as caries progress?

    <p>Undercutting of enamel layers</p> Signup and view all the answers

    What characterizes the Zone of Destruction?

    <p>It is clinically observed as dark brown, soft and mushy.</p> Signup and view all the answers

    Which of the following is true about the Zone of Penetration?

    <p>Bacterial invasion occurs within this zone.</p> Signup and view all the answers

    What is the primary consequence of the high bacterial load in the Zone of Destruction?

    <p>Formation of transverse clefts.</p> Signup and view all the answers

    Why is removal necessary in the Zone of Destruction?

    <p>It cannot be repaired and provides inadequate restoration support.</p> Signup and view all the answers

    How does the presence of acid from bacteria affect dentine in the Zone of Penetration?

    <p>It decalcifies the dentine.</p> Signup and view all the answers

    What is a notable feature of the Zone of Demineralisation?

    <p>It implies that mineral content is lost.</p> Signup and view all the answers

    What distinguishes translucent dentine from other zones?

    <p>It reflects changes in mineral properties.</p> Signup and view all the answers

    In which condition might clinicians choose not to remove the Zone of Penetration?

    <p>When conservative management is preferred.</p> Signup and view all the answers

    How does the collagen matrix respond to bacterial enzymes in the Zone of Destruction?

    <p>It is denatured by proteolytic enzymes.</p> Signup and view all the answers

    Study Notes

    Histopathology of Enamel and Dentine Caries

    • The histopathology of enamel and dentine caries is a topic in Oral and Dental Science.
    • GDC learning outcomes include describing oral diseases, their relevance to prevention diagnosis and treatment, explaining the etiology and pathogenesis of oral disease, and describing relevant dental, oral, craniofacial, and general anatomy to apply to patient management.
    • Pre-reading includes 'Aetiology of Dental Caries' and 'Histology of enamel and dentine' lectures.
    • Caries is influenced by time, susceptible tooth surface, plaque bacteria, and fermentable carbohydrates.
    • The decreasing pH causes demineralisation of tooth surface (hydroxyapatite).
    • ICDAS (International Caries Detection and Assessment System) is a clinical scoring system used to diagnose, characterize, and stage caries progression.

    Histopathology of Dentine Caries

    • Learning objectives include describing the clinical appearance of dentine caries, its histology, identifying and naming the four zones of destruction, and identifying dentine mechanisms for pulp protection.

    Recap on Caries Aetiology

    • A lower pH demineralizes tooth enamel (hydroxyapatite) breaking it down into component ions.
    • If pH does not neutralize this process, it develops into dental caries.

    How do we know this is happening clinically?

    • ICDAS scores are used at various stages of caries diagnosis.

    ICDAS Scores

    • ICDAS is a system for detecting and assessing caries.
    • It's used for clinical research, clinical practice, and epidemiological purposes.
    • Allows for diagnosis of caries at each stage.
    • Accounts for inconsistencies in caries diagnosis.

    Moderate Stage Caries (ICDAS Code 4)

    • Features include a dark shadow from dentin, possible enamel breakdown, white or brown spots when wet, and a darkened intrinsic shadow (grey, blue, brown).

    Extensive Stage Caries (ICDAS Code 5/6)

    • ICDAS code 5 features a distinct cavity in opaque or discolored enamel with visible dentin and visible evidence of demineralization (white or brown walls).
    • ICDAS code 6 features an extensive cavity visibly extending into dentin.

    Recap on the Structure of Dentine

    • Dentine's mineral component is hydroxyapatite.
    • Organic material is collagen.
    • Dentinal tubules permeate the tissue with odontoblast processes.
    • Dentine-pulp complex protects the pulp.

    How does dentine caries progress through each stage to give these ICDAS scores?

    • Caries progression from enamel to dentine shows a change in substrate hardness, which causes lateral spread under the enamel and leads to grey shadowing, and eventual crown disintegration.
    • This is similar to the erosion of a cliff with bacteria as water.

    Macroscopic Dentine Caries - ICDAS Code 4

    • Progression from enamel to dentin indicates a change in the hardness of the substrate.
    • This causes lateral spread of caries beneath the enamel.
    • This leads to grey shadowing.
    • This eventually leads to breakdown.

    Macroscopic Dentine Caries - ICDAS Code 5/6

    • As enamel becomes further undermined and breaks away, it leads to dentin exposure (5), then a more extensive cavity (6).
    • More destruction makes restoration harder.
    • Bacterial destruction makes dentine softer.

    How does this clinical appearance translate to histological appearance?

    • The microscopic approach reveals "undercutting" of enamel as caries progresses along the ADJ (adjacent) through softer dentin.

    Microscopic Dentine Caries

    • This sample displays undercutting of enamel. This occurs as caries progresses along the adjacent dentin and illustrates different caries patterns from the enamel.
    • Microscopic dentin caries (4, 5 and 6) are assessed clinically as affected or infected zones.

    Affected vs Infected Dentine

    • There are different macroscopic and microscopic interpretations for affected and infected dentin, zones of destruction, penetration, demineralization, translucent dentin, and tertiary dentin. These are used in clinical caries diagnosis.

    Zone 1 - Zone of Destruction

    • The outermost superficial zone is clinically diagnosed as dark brown, soft, and mushy.
    • With rapid caries it may be soft and yellow with slow progression being harder.
    • The mineral content is dissociated due to bacterial acid.
    • Collagen matrix is denatured by enzymes.
    • High bacterial load destroys dentin tubules with liquefaction foci.
    • Cracks are termed transverse clefts.

    Zone 2 - Zone of Penetration/Bacterial Invasion

    • Within this zone the dentin structure is still present.
    • Tubules are not liquefied.
    • Bacteria decalcify the dentin.
    • This zone also dissolves proteins.
    • Many clinicians believe that this area needs to be cleaned.
    • This area must be removed, otherwise the caries process continues.

    Zone 3 - Zone of Demineralisation

    • Acid spreads from higher zones to un-occluded tubules.
    • Demineralisation of dentine occurs easily.
    • No bacteria are found within this zone.
    • Zone 3 is the advancing front of the lesion.
    • This zone can be very small (less than 1mm).

    Zone 4 - Translucent (Sclerotic) Zone

    • Occurs when acid initially penetrates and stimulates odontoblast processes.
    • Calcification occurs inside tubules, producing hyper-mineralization.
    • Tubules become 'plugged' with mineral to slow acid and toxin penetration protecting the pulp.
    • This shows up radiographically as a whiter area.
    • It does not need to be removed.

    Zone 5 - Tertiary Dentin

    • This is new dentine laid down around the pulp-dentine border.
    • It is not truly a zone but part of the caries process.
    • Formed to create more dentine between the pulp and the lesion, for pulp protection.
    • Tertiary dentine is produced when the pulp becomes mildly inflamed by advancing acid.
    • It has an irregular tubular structure and comes in two types.

    Video for Review

    • A video summarizing the process of this topic is available at the given URL.

    Thank You!

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Histopathology of Dentine Caries PDF

    Description

    This quiz focuses on the histopathology of enamel and dentine caries, a crucial topic in Oral and Dental Science. It covers the etiology, pathogenesis, and clinical appearances of dental caries, alongside methods for diagnosis and treatment. Prepare to demonstrate your understanding of the key concepts relevant to oral diseases.

    More Like This

    Histopathology of Enamel and Dentine Caries
    39 questions

    Histopathology of Enamel and Dentine Caries

    HandierMemphis avatar
    HandierMemphis
    Histopathology of Enamel and Dentine Caries
    45 questions

    Histopathology of Enamel and Dentine Caries

    HandierMemphis avatar
    HandierMemphis
    Histopathology Dentine Caries medium
    48 questions

    Histopathology Dentine Caries medium

    WiseTropicalIsland4758 avatar
    WiseTropicalIsland4758
    Histopathology of Dentine Caries hard
    48 questions

    Histopathology of Dentine Caries hard

    WiseTropicalIsland4758 avatar
    WiseTropicalIsland4758
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser