Dental Caries and Carbohydrates Quiz
50 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

Which type of carbohydrates is considered the most cariogenic?

  • Disaccharides (correct)
  • Oligosaccharides
  • Polysaccharides
  • Monosaccharides

What role do lactobacilli play in dental caries?

  • They progress dental caries. (correct)
  • They prevent dental caries.
  • They do not play a role in dental caries.
  • They initiate dental caries.

Which of the following factors makes sucrose particularly cariogenic?

  • It diffuses slowly into dental plaque.
  • It is broken down rapidly by bacterial enzymes. (correct)
  • It is a polysaccharide.
  • It is expensive and hard to find.

What is the primary component produced by cariogenic bacteria during the breakdown of sucrose?

<p>Dextran and Levan (B)</p> Signup and view all the answers

Why are polysaccharides less cariogenic compared to disaccharides?

<p>They are not easily metabolized by oral bacteria. (A)</p> Signup and view all the answers

Which bacterium is primarily associated with the production of dental plaque due to sucrose metabolism?

<p>Streptococcus mutans (D)</p> Signup and view all the answers

What happens during the hydrolysis of sucrose?

<p>It results in the formation of glucose and fructose. (C)</p> Signup and view all the answers

Which of the following statements about the cariogenicity of carbohydrates is true?

<p>Disaccharides are more cariogenic than monosaccharides. (D)</p> Signup and view all the answers

How does an increase in the amount of carbohydrate intake affect caries activity?

<p>It increases caries activity. (B)</p> Signup and view all the answers

Which factor contributes most to increased caries susceptibility from carbohydrate intake?

<p>Duration of the oral acid exposure. (A)</p> Signup and view all the answers

What characteristic of sticky carbohydrates contributes to their cariogenicity?

<p>They remain in the mouth longer, allowing more acid production. (A)</p> Signup and view all the answers

What is true about refined carbohydrates concerning their effect on dental health?

<p>They increase adhesiveness and cariogenic potential. (A)</p> Signup and view all the answers

Which carbohydrate is considered non-cariogenic despite being refined?

<p>Xylitol (A)</p> Signup and view all the answers

In the Vipeholm Experiment, what was one significant finding regarding sticky carbohydrates?

<p>Toffees and caramels exhibited the highest caries activity. (D)</p> Signup and view all the answers

What happens to the pH level in the mouth after consuming carbohydrates?

<p>It gradually decreases and takes time to return to normal. (D)</p> Signup and view all the answers

Which of the following is NOT a reason why frequent carbohydrate intake increases caries risk?

<p>Immediate normalization of mouth pH. (C)</p> Signup and view all the answers

What happens when demineralization periods exceed remineralization periods?

<p>Caries is produced. (B)</p> Signup and view all the answers

Which type of tooth morphology is more susceptible to caries?

<p>Deep and narrow pits (D)</p> Signup and view all the answers

Which of the following factors is least significant in the initiation of caries?

<p>Genetic tooth morphology (D)</p> Signup and view all the answers

What is the role of fluoride in dental health?

<p>It enhances remineralization and inhibits bacterial growth. (A)</p> Signup and view all the answers

Which condition makes newly erupted teeth more susceptible to caries?

<p>Incomplete mineralization (B)</p> Signup and view all the answers

What type of fissures are generally more caries resistant?

<p>U type fissures (C)</p> Signup and view all the answers

How can fluoride aid in increasing enamel resistance to acids?

<p>By replacing hydroxyl groups in hydroxyapatite. (D)</p> Signup and view all the answers

Which of the following is an environmental factor affecting caries development?

<p>Dental hygiene practices (B)</p> Signup and view all the answers

What characteristic of the early enamel lesion is described by its cone shape?

<p>Base on the enamel surface (A)</p> Signup and view all the answers

Which zone of the early smooth surface enamel caries represents initial demineralization?

<p>Translucent zone (A)</p> Signup and view all the answers

What do submicroscopic pores in the enamel account for, in terms of total enamel volume?

<p>1% (B)</p> Signup and view all the answers

What causes the dark appearance of the dark zone when viewed by transmitted light?

<p>Small pores allowing air to pass and scatter light (A)</p> Signup and view all the answers

Which method is used to determine the percentage of enamel pores by volume?

<p>Polarized light microscope (C)</p> Signup and view all the answers

What is the consequence of the structural features being lost in the translucent zone?

<p>Limited visibility under the microscope (A)</p> Signup and view all the answers

In microradiography, how are differences in the amount and distribution of minerals reflected?

<p>By black and white representation (A)</p> Signup and view all the answers

What is believed to cause the smaller pores in the dark zone?

<p>Remineralization during non-acid periods (A)</p> Signup and view all the answers

What distinguishes infected dentinal lesions from uninfected dentinal lesions?

<p>Infected lesions are not remineralizable (B)</p> Signup and view all the answers

Which zone is not associated with uninfected dentinal lesions?

<p>Zone of Liquefaction (A)</p> Signup and view all the answers

What is the primary cause of root surface caries?

<p>Exposure of the tooth neck due to gingival recession (D)</p> Signup and view all the answers

Which reactionary change in dentin occurs due to severe stimuli?

<p>Dead tract (B)</p> Signup and view all the answers

What characterizes tubular sclerosis in dentin?

<p>Reduction in the size of dentinal tubules (C)</p> Signup and view all the answers

What is a characteristic feature of regular reactionary dentin?

<p>Tubular structure at the dentin-pulp interface (C)</p> Signup and view all the answers

Which of the following zones is primarily associated with affected dentinal lesions?

<p>Zone of Fatty Degeneration (C)</p> Signup and view all the answers

Which statement accurately describes bacteria's role in root surface caries?

<p>Bacteria invade the superficial layer of demineralized cementum (B)</p> Signup and view all the answers

What occurs during the phase of bacterial invasion in enamel caries?

<p>Minerals are removed allowing bacteria to invade. (B)</p> Signup and view all the answers

What is the primary result of the destruction phase in enamel caries?

<p>Loss of structural integrity of enamel. (C)</p> Signup and view all the answers

What happens to enamel when acids reach the dentino-enamel junction (DEJ)?

<p>Lateral spread of acids weakens enamel. (C)</p> Signup and view all the answers

What characterizes an uninfected dentinal lesion during early caries development?

<p>Acid attack without cavitation. (B)</p> Signup and view all the answers

What is observed in the zone of hypermineralization in dentinal lesions?

<p>An increase in mineral density. (A)</p> Signup and view all the answers

Which component forms the bulk of the dentin matrix?

<p>Dentin tubules. (A)</p> Signup and view all the answers

What occurs in the zone of fatty degeneration during dentinal caries?

<p>Odontoblastic processes collapse due to acid irritation. (D)</p> Signup and view all the answers

How much of the dentin's composition is made up of organic material?

<p>20% (D)</p> Signup and view all the answers

Signup and view all the answers

Signup and view all the answers

Flashcards

Pioneer Organisms in Dentin Caries

Bacteria that are found in large numbers in dentin caries and are considered the first to colonize the area.

Lactobacilli

A type of bacteria that was once used as an indicator of high caries activity because they are found in high numbers in the saliva of people with a lot of cavities.

Fermentable Carbohydrates

Sugars, including glucose, fructose, sucrose, maltose, lactose, starch and glycogen, that are broken down by bacteria to produce acids that damage teeth.

Sucrose

A type of sugar that is particularly bad for teeth because it's easily broken down by bacteria and helps them stick to teeth.

Signup and view all the flashcards

Dextran

A sticky substance produced by bacteria from sucrose that helps them stick to teeth and form plaque.

Signup and view all the flashcards

Levan

Another sticky substance produced by bacteria from sucrose that also helps them stick to teeth and form plaque.

Signup and view all the flashcards

Polysaccharides

Large sugar molecules that are less likely to cause cavities because they are difficult for bacteria to break down.

Signup and view all the flashcards

Amylase

An enzyme in saliva that breaks down starch (polysaccharides) into simpler sugars.

Signup and view all the flashcards

Caries and Carbohydrate Intake

The more sugar you consume, the higher the risk of cavities.

Signup and view all the flashcards

Frequency of Sugar Intake

Frequent sugary snacks throughout the day increase the time bacteria have to produce acid, leading to tooth decay.

Signup and view all the flashcards

Sticky Carbohydrates

Sugary foods that stick to your teeth for a long time, like candy, are more likely to cause cavities.

Signup and view all the flashcards

Refined Carbohydrates

Refined sugars, like white sugar, are more likely to cause cavities because they are concentrated and easily broken down by bacteria.

Signup and view all the flashcards

Vipeholm Experiment

A study that investigated the relationship between different types and amounts of carbohydrates and the development of tooth decay.

Signup and view all the flashcards

Vipeholm Experiment Results

The Vipeholm experiment showed sticky sweets eaten between meals led to the highest rate of cavities.

Signup and view all the flashcards

Xylitol

Xylitol is a sugar substitute that doesn't promote bacterial growth, making it good for your teeth.

Signup and view all the flashcards

Honey and Caries

Honey, although not refined, is highly cariogenic due to its high sugar content.

Signup and view all the flashcards

Demineralization

Process where minerals are lost from tooth enamel, often due to acids produced by bacteria.

Signup and view all the flashcards

Remineralization

Process of rebuilding tooth enamel by restoring lost minerals, often aided by fluoride.

Signup and view all the flashcards

Dental Caries

Tooth decay caused by demineralization exceeding remineralization.

Signup and view all the flashcards

Arrested Caries

Tooth decay that has stopped progressing due to remineralization being greater than demineralization.

Signup and view all the flashcards

Tooth Resistance

The ability of a tooth to withstand demineralization and resist decay.

Signup and view all the flashcards

Enamel

Tooth enamel is the hard outer layer of a tooth.

Signup and view all the flashcards

Cariostatic

Fluoride's action of making tooth enamel stronger and more resistant to demineralization.

Signup and view all the flashcards

Fluoride Enhances Remineralization

Fluoride's ability to promote the remineralization of dental enamel.

Signup and view all the flashcards

Phase of demineralization

The initial phase of tooth decay where acids produced by bacteria dissolve the enamel.

Signup and view all the flashcards

Phase of bacterial invasion

The stage of tooth decay where bacteria invade the tooth structure through pores created by dissolving enamel.

Signup and view all the flashcards

Phase of destruction

The final stage of tooth decay where the tooth undergoes a significant loss of structure and the organic matter is broken down by bacteria.

Signup and view all the flashcards

Secondary enamel caries

The spread of decay laterally beneath the enamel, weakening the tooth.

Signup and view all the flashcards

Uninfected dentin lesion

The initial stage of dentin decay where acids affect the dentin, irritating the odontoblastic processes.

Signup and view all the flashcards

Zone of fatty degeneration

A zone in the dentin where the odontoblastic processes are damaged by acids.

Signup and view all the flashcards

Zone of hypermineralization

A zone in the dentin where the tubules become more mineralized, potentially slowing down the spread of decay.

Signup and view all the flashcards

Initial Enamel Caries

The earliest stage of enamel caries, characterized by a cone-shaped lesion with the base on the enamel surface and the apex towards the dentin.

Signup and view all the flashcards

Translucent Zone

The first zone of an early enamel caries lesion, located on the front of the lesion towards the dentin. It appears translucent due to the filling of submicroscopic pores with mounting media, like quinoline, which has the same refractive index as enamel.

Signup and view all the flashcards

Dark Zone

The second zone of an early enamel caries lesion, located superficial to the translucent zone. It appears dark, due to smaller pores that don't allow the mounting media to enter, scattering light.

Signup and view all the flashcards

Microradiography

A microscopic technique used to analyze the amount and distribution of minerals in a sample, like teeth. It shows minerals as black and white, indicating denser areas as black.

Signup and view all the flashcards

Microhardness Testing

A technique used to measure the hardness of microscopic sections, often used to assess tooth enamel strength.

Signup and view all the flashcards

Polarized Light Microscopy

A technique using polarized light to determine the percentage of pores by volume within enamel. It helps understand the porosity and strength of the enamel.

Signup and view all the flashcards

Submicroscopic Pores

Submicroscopic spaces that form in the enamel during the early stages of caries, caused by the diffusion of hydrogen ions. These pores are filled with mounting media in microscopic sections.

Signup and view all the flashcards

Dentinal Destruction (Superficial Zone)

The area of dentinal destruction is characterized by coalescing liquefaction foci and transverse clefts forming cavities filled with microorganisms and debris, ultimately leading to fatty degeneration.

Signup and view all the flashcards

Infected Dentinal Lesion

This zone is marked by the presence of fatty degeneration and a lack of remineralization, indicating irreversible damage.

Signup and view all the flashcards

Tubular Sclerosis

This is a type of reaction to damage where peritubular dentin (the layer around the dentinal tubules) shrinks in response to acid attacks and bacterial invasions, effectively reducing the size of the tubules.

Signup and view all the flashcards

Dead Tract

This occurs when severe damage results in the death of odontoblasts, leaving empty, dark-colored tubules.

Signup and view all the flashcards

Regular Reactionary Dentin

This is a milder reaction to damage, forming dentin with a normal tubular structure at the dentin-pulp interface.

Signup and view all the flashcards

Irregular Reactionary Dentin

This occurs when the damage is more severe, resulting in the formation of dentin with an irregular structure, ranging from irregular tubules to disorganized bone-like tissue.

Signup and view all the flashcards

Root Surface Caries

This happens when the neck of a tooth is exposed to the oral environment due to gingival recession, often caused by periodontal diseases or aging.

Signup and view all the flashcards

Study Notes

Dental Caries Definition and Etiology

  • Dental caries is a progressive microbial disease affecting hard tooth structures.
  • It's characterized by demineralization of the inorganic portion and destruction of the organic substance of the tooth.
  • Contributing factors to dental caries:
    • Cariogenic bacteria (agent)
    • Fermentable carbohydrates (substrate)
    • Susceptible tooth and saliva (host)
    • Time
    • Means of microorganism and substrate localization on tooth surfaces (dental plaque).

Role of Bacteria in Dental Caries

  • Cariogenic bacteria produce acids from the fermentation of carbohydrates.
  • These acids lead to enamel and dentin demineralization.

Experiments Demonstrating the Role of Cariogenic Microorganisms

  • Miller's experiment demonstrated that caries-like lesions form in saliva when carbohydrates are added.
  • Caries result from carbohydrate fermentation by bacteria in saliva.
  • Initial experiment established that bacteria is necessary for caries formation.
  • Orland's experiment showed that germ-free animals don't develop caries, concluding bacteria is essential for caries formation.

Production of Gnotobiotes

  • Aim: to determine which bacteria produce dental caries.
  • Rats were divided into groups and fed specific micro-organisms (streptococci, staphylococci, lactobacilli, etc.).
  • Streptococcus mutans produced smooth surface and pit-and-fissure caries.
  • Lactobacilli produced pit-and-fissure caries.
  • Not all bacteria cause dental caries.
  • Streptococcus mutans is more cariogenic than lactobacilli.

Essential Features for Cariogenic Bacteria

  • Ability to produce acids (acidogenic).
  • Ability to survive in acidic environments (aciduric).
  • Synthesis of insoluble extracellular polysaccharides (dextrans and levans).
  • Synthesis and utilization of intracellular storage polysaccharides (amylopectin).
  • Ability to actively transport fermentable sugars.
  • Attachment mechanisms for firm adhesion to tooth surfaces.

Cariogenic Bacteria: Streptococcus Mutans and Lactobacillus Species

  • Streptococcus mutans:
    • Acidogenic, acid-tolerant.
    • Synthesizes extracellular polysaccharides (dextrans and levans) for adhesion.
    • Undergoes morphological mutations with changing environmental conditions (pH).
  • Lactobacillus species:
    • Acidogenic, acid-tolerant.
    • Can only produce pit and fissure caries in gnotobiotic animals.
    • Do not produce extracellular polysaccharides for adhesion.

Role of Fermentable Carbohydrates

  • Types of carbohydrates: monosaccharides (e.g., glucose, fructose), disaccharides (e.g., sucrose, maltose, lactose), and polysaccharides (e.g., starch, glycogen).
  • Sucrose is the most cariogenic carbohydrate.
  • Sucrose is cheap, highly available, low molecular weight and dissolves easily into dental plaque.
  • Bacterial enzymes rapidly break down sucrose producing acids.
  • Sucrose with the help of cariogenic bacteria (e.g., Streptococcus mutans) forms extracellular polysaccharides (dextran & levan).

Refinement of Carbohydrate

  • Refinement of carbohydrates increase cariogenicity.
  • Refinement increases the concentration of fermentable carbohydrates.
  • Refinement removes fibrous material increasing adhesiveness.
  • Xylitol, a refined carbohydrate, is not cariogenic.
  • Honey is cariogenic despite not being refined.

Vipeholm Experiment

  • Aim: to determine the effect of the amount, frequency, and texture of carbohydrates on caries susceptibility.
  • High caries activity correlated with frequent intake of sticky carbohydrates.
  • Caries in groups consuming sugar between meals was less severe than consumption between meals.

3. Dental Plaque

  • Definition: a tenacious bacterial structure formed on tooth surfaces.
  • Composition: Microorganisms, proteins, carbohydrates, and inorganic content.
  • Role of plaque matrix: acts as a diffusion-limiting membrane, slow down saliva action & contributes to adhesiveness.
  • Factors affecting formation & thickness: Tooth anatomy, appliances, surface structure, friction, oral hygiene measures, and diet.

Mechanism of Bacterial Plaque Formation

  • Formation of an acquired enamel pellicle (acellular).
  • Colonization of cell-free pellicle by pioneer bacteria.
  • Rapid growth phase of bacteria spreading across the tooth surface.
  • Formation of an intermediate/mature community.
  • Selective replacement of microbes in the mature community.

Microbial Succession

  • Aciduric organisms (e.g., Streptococcus mutans (positive interaction)) proliferate, while less aciduric organisms such as S. sanguis (negative interaction) disappear.
  • Aerobic species are replaced by anaerobic species.

Biochemical Reactions in Bacterial Plaque

  • Acid production.
  • Formation of extracellular and intracellular polysaccharides.
  • Demineralization and remineralization phases.

Stephan's Experiment

  • Aim: to study pH changes in plaque after glucose intake.
  • pH rapidly decrease within 2-5 minutes of glucose ingestion.
  • Return to resting pH is slow and depends on caries activity.

Demineralization and Remineralization

  • Caries is an alternating process of demineralization and remineralization.
  • Remineralization occurs when the consumption of fermentable sugars stops and oral hygiene improves.

Host Factors: Susceptible Tooth

  • Position (upper/lower, anterior/posterior, aligned/malaligned teeth).
  • Morphology (pits and fissures are more susceptible to caries).
  • Structure (enamel hypoplasia, hypocalcification).
  • Fluoride (higher fluoride content increases resistance to caries).

Host Factors: Saliva

  • Salivary glycoproteins initially protect enamel.
  • Saliva helps cleanse the mouth.
  • Salivary buffers neutralize acidic pH.
  • Lower saliva flow rates increase caries incidence.

Pathology of Dental Caries

  • Macroscopic appearance: opaque chalky white areas (white spots).
  • Microscopic changes: demineralization and remineralization phases.
  • Phases of enamel caries: initiation, bacterial invasion, destruction, and secondary enamel caries.
  • Dentin caries: initial non-bacterial lesions, acid attack on dentinal tubules leading to acid-induced demineralization.

Methods to Identify Initial Enamel Caries

  • Ordinary light microscope, polarizing light microscope, microradiography, and microhardness testing.

Zones in Longitudinal Ground Sections of Enamel

    1. Translucent zone: initial demineralization, appears translucent.
    1. Dark zone: further demineralization.
    1. Body of the lesion: most demineralization.
    1. Surface zone: remineralization zone.

Studying That Suits You

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

Quiz Team

Related Documents

Dental Caries Handout PDF

Description

Test your knowledge about the relationship between carbohydrates and dental caries. This quiz covers the cariogenicity of different types of carbohydrates, the role of bacteria, and the impact of carbohydrate intake on dental health. Explore the factors influencing dental plaque formation and caries susceptibility.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser