Podcast
Questions and Answers
What is the primary etiologic factor for gingivitis and periodontitis?
What is the primary etiologic factor for gingivitis and periodontitis?
Which of the following is characterized by the presence of crevicular fluid?
Which of the following is characterized by the presence of crevicular fluid?
What are the soft accumulations of bacteria and tissue cells that lack the organized structure of dental plaque?
What are the soft accumulations of bacteria and tissue cells that lack the organized structure of dental plaque?
Which ecosystem is NOT part of the six major niches involved in periodontal microbiology?
Which ecosystem is NOT part of the six major niches involved in periodontal microbiology?
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What is the nature of calculus deposits on teeth?
What is the nature of calculus deposits on teeth?
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Which of the following statements about dental plaque is incorrect?
Which of the following statements about dental plaque is incorrect?
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Which bacterial complexes are involved in periodontal disease?
Which bacterial complexes are involved in periodontal disease?
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Which factor has a profound effect on periodontal treatment?
Which factor has a profound effect on periodontal treatment?
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Which of the following microorganisms is primarily associated with chronic periodontitis?
Which of the following microorganisms is primarily associated with chronic periodontitis?
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What type of plaque is primarily composed of gram-positive facultative species in periodontal health?
What type of plaque is primarily composed of gram-positive facultative species in periodontal health?
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Which microorganisms are commonly found in pregnancy-associated gingivitis?
Which microorganisms are commonly found in pregnancy-associated gingivitis?
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According to the ecological plaque hypothesis, which factor is considered important for oral health?
According to the ecological plaque hypothesis, which factor is considered important for oral health?
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Which type of plaque is most commonly associated with soft tissue destruction?
Which type of plaque is most commonly associated with soft tissue destruction?
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What is the most effective method for controlling dental plaque biofilm?
What is the most effective method for controlling dental plaque biofilm?
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Localized aggressive periodontitis is primarily linked to which bacteria?
Localized aggressive periodontitis is primarily linked to which bacteria?
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What percentage of dental plaque is composed of microorganisms?
What percentage of dental plaque is composed of microorganisms?
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Which component is NOT part of the intercellular matrix in dental plaque?
Which component is NOT part of the intercellular matrix in dental plaque?
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What is the predominant form of polysaccharides produced by bacteria in dental plaque?
What is the predominant form of polysaccharides produced by bacteria in dental plaque?
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Which of the following is primarily derived from salivary components within the intercellular matrix?
Which of the following is primarily derived from salivary components within the intercellular matrix?
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Which bacteria lifestyle does NOT contribute to biofilm formation?
Which bacteria lifestyle does NOT contribute to biofilm formation?
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What percentage of bacteria on Earth are believed to live as attached bacteria in biofilms?
What percentage of bacteria on Earth are believed to live as attached bacteria in biofilms?
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What is the main role of the extracellular slime layer in biofilms?
What is the main role of the extracellular slime layer in biofilms?
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Which inorganic materials are considered main components of the intercellular matrix in plaque biofilm?
Which inorganic materials are considered main components of the intercellular matrix in plaque biofilm?
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What initiates the formation of a biofilm community on a solid surface?
What initiates the formation of a biofilm community on a solid surface?
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What role do glycoproteins play in dental plaque formation?
What role do glycoproteins play in dental plaque formation?
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Which cluster is particularly associated with bleeding on probing?
Which cluster is particularly associated with bleeding on probing?
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What mechanism allows two species that do not usually coaggregate to connect?
What mechanism allows two species that do not usually coaggregate to connect?
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Which of the following species is predominantly found at the tooth surface in dental plaque?
Which of the following species is predominantly found at the tooth surface in dental plaque?
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Which statement about secondary colonizers in dental plaque is accurate?
Which statement about secondary colonizers in dental plaque is accurate?
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Which type of bacteria generally predominate in the outer surface of mature plaque?
Which type of bacteria generally predominate in the outer surface of mature plaque?
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What is the primary energy source used by bacterial species at the tooth surface?
What is the primary energy source used by bacterial species at the tooth surface?
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Which of the following is NOT a predominant species found in the gram-positive group at the tooth surface?
Which of the following is NOT a predominant species found in the gram-positive group at the tooth surface?
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The interaction between periodontal pathogens within the biofilm is often characterized by which two key strategies?
The interaction between periodontal pathogens within the biofilm is often characterized by which two key strategies?
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Which complex includes species recognized as pathogens in various infections?
Which complex includes species recognized as pathogens in various infections?
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What is a key characteristic of biofilms formed by periodontal pathogens?
What is a key characteristic of biofilms formed by periodontal pathogens?
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What is the primary function of the glycoprotein pellicle formed in the oral cavity?
What is the primary function of the glycoprotein pellicle formed in the oral cavity?
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Which type of microorganisms predominantly colonize the pellicle-coated tooth surface initially?
Which type of microorganisms predominantly colonize the pellicle-coated tooth surface initially?
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What role do fimbriae play in the formation of dental plaque?
What role do fimbriae play in the formation of dental plaque?
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What type of environment is found as dental plaque matures?
What type of environment is found as dental plaque matures?
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Which microorganisms are classified as secondary colonizers in dental plaque?
Which microorganisms are classified as secondary colonizers in dental plaque?
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What initial interactions facilitate coaggregation in dental plaque formation?
What initial interactions facilitate coaggregation in dental plaque formation?
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What is the significance of adhesins in bacteria colonizing the pellicle?
What is the significance of adhesins in bacteria colonizing the pellicle?
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Which of the following components is NOT part of the glycoprotein pellicle?
Which of the following components is NOT part of the glycoprotein pellicle?
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The transition from early plaque to mature plaque is characterized by an increase in which type of bacteria?
The transition from early plaque to mature plaque is characterized by an increase in which type of bacteria?
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Microbial ecology in dental plaque is classified into how many clusters based on the bacteria's nutritional and atmospheric requirements?
Microbial ecology in dental plaque is classified into how many clusters based on the bacteria's nutritional and atmospheric requirements?
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Study Notes
Microbiology of Periodontal Diseases
- Periodontal diseases are a complex issue involving the host, oral environment, and treatment.
- A profound knowledge of periodontal microbiology is necessary to understand and manage these diseases.
- There are different types of tooth deposits that influence periodontal disease: dental plaque, materia alba, and calculus.
- Dental plaque is a soft biofilm that adheres to teeth and restorations.
- Materia alba is a soft accumulation of bacteria and tissue debris, easily removable.
- Calculus is a hard deposit formed by mineralized dental plaque.
Learning Objectives
- Understand tooth deposits, their formation, and implications for disease.
- Recognize bacterial complexes and families involved in periodontal disease.
- Understand bacterial interactions in various periodontal diseases.
- Correlate periodontal treatment modalities with microbial reasons.
Bacterial Classification
- Gram-negative bacteria are predominantly found in subgingival/periodontal/periimplant pockets at different timeframes after birth.
- Gram-positive bacteria are often found in the initial stages in the mouth, for a period before and after birth..
- Additional types of microorganism exists and are present in the mouth; in addition to bacteria.
Six Major Ecosystems
- Intraoral and supragingival hard surfaces (teeth, implants, restorations, prostheses)
- Subgingival regions adjacent to hard surfaces (periodontal/periimplant pockets).
- Buccal/palatal epithelium and the epithelium of the floor of the mouth.
- Dorsum of the tongue
- Tonsils
- Saliva
Human Oral Microbiota
- Commensals
- Symbiotic species
- Pathogenic species.
Composition of Dental Plaque
- 70% Microorganisms (mostly bacteria: >500 strains).
- 30% Intercellular Matrix (organic and inorganic materials).
Organic Materials
- Glycoproteins (derived from saliva, pellicle component).
- Polysaccharides (produced by bacteria, commonly dextran).
- Albumin (from crevicular fluid).
- Lipids (membrane debris, host cells, and food debris).
Inorganic Materials
- Calcium and phosphorus (main components).
- Sodium, potassium, and fluoride (trace amounts).
- Derived from saliva, gingival crevicular fluid, and fluoridated toothpaste.
Bacterial Lifestyles
- Free-floating (planktonic)
- Attached to a surface forming a biofilm community.
Bacterial Biofilm Communities
- A biofilm is a well-organized community of bacteria adhering to surfaces and embedded in an extracellular slime layer.
- More than 99% of all bacteria on Earth live as attached bacteria.
- Biofilms are found on medical/dental devices (e.g., implants).
- Formed via bacterial interactions with a solid surface. Physical & physiological interactions among species take place within the microbial mass then.
- Biofilms show increased resistance to antimicrobials. The limited diffusion of substances into the matrix, slow cell growth rate within the biofilm environment. Altered bacterial properties resulting from growth on surfaces make the bacteria more resistant.
Plaque Formation Phases
- Pellicle Formation (initial layer coating the tooth surface).
- Initial Colonization (bacteria predominantly gram-positive).
- Secondary Colonization (non-initial bacteria adhering to/coaggregating with existing colonies).
- Plaque Maturation (further growth and colonization of microorganisms, transition to anaerobic environment).
Formation of Dental Plaque
- May be readily visualized on teeth after 1-2 days without oral hygiene.
- Appears as white, grayish, or yellow.
- Typically observed on the gingival third of the tooth surface.
- Forms preferentially in cracks, pits, fissures, under overhanging restorations, around malaligned teeth.
- Location and rate depend on oral hygiene, diet, salivary composition, and saliva flow rate
- Absence of oral hygiene - plaque continues to accumulate.
- The process involves 3 phases (1-formation of pellicle, 2-initial colonization, 3-secondary colonization, 4-plaque maturation).
Plaque Index
- Method for measuring plaque amount.
- Plaque is stained using disclosing tablets (or other similar methods).
- The amount of plaque is calculated based on the number of stained sites vs. total number of sites.
Microbiologic Specificity of Periodontal Diseases
- Nonspecific Plaque Hypothesis
- Specific Plaque Hypothesis
- Ecological Plaque Hypothesis
Microorganisms Associated with Specific Periodontal Diseases
- Periodontal Health (Gram-positive facultative bacteria; Streptococcus and Actinomyces species)
- Gingivitis (almost equal proportions of gram-positive and gram-negative bacteria)
- Localized Aggressive Periodontitis (90% A. actinomycetemcomitans)
- Pregnancy Gingivitis/Associated with Pregnancy (P. intermedia using steroids as growth factors)
- Chronic Periodontitis (high percentage anaerobic gram-negative bacteria; P. gingivalis, P. intermedia, F. nucleatum, and B. forsythus. Herpesviruses EBV-1 and HCMV have been linked to this)
- Abscesses of the Periodontium (F. nucleatum, P. intermedia, P. gingivalis, P. micros, B. forsythus)
Controlling Dental Plaque Biofilm
- Mechanical removal is the most effective method currently available.
Different Plaque Regions and Associated Diseases
- Supragingival plaque - calculus and caries, gingivitis
- Marginal plaque - calculus and caries, gingivitis
- Subgingival plaque- calculus and caries, soft tissue destruction
- Tooth-associated plaque
- Tissue-associated plaque
Key Points
- Importance of subgingival niche (ecosystem).
- Gingivitis VS Periodontitis.
- Plaque is the primary factor for gingivitis and periodontitis.
- Shifts in microbial communities as periodontitis progresses.
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Description
This quiz delves into the microbial aspects of periodontal diseases, highlighting the importance of understanding tooth deposits such as dental plaque, materia alba, and calculus. Participants will explore bacterial interactions, classifications, and treatment modalities associated with periodontal conditions. Enhance your knowledge of the complex relationship between oral microbiology and periodontal health.
