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74 Cards in this Set
- Front
- Back
What is the primary etiologic agent initiation dental caries?
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Streptococcus mutans
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The bacteria that produce dental caries must have the ability to produce what?
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Insoluble Glucans
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What are two types of glucans that are both polymers of glucose?
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Dextrans and Mutans
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What types of bacteria produce dextrans and mutans?
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Streptococcus Sanguis
mutans salivarius lactobacillus |
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What are polymers of fructose?
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Levans
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What bacteria produce levans?
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Streptococcus salivarius
mutans sanguis lactobacillus casei acidophilus |
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what is a gram-negative coccobacillary rod?
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Actinobacillus
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What bacteria is found in the normal flora in the upper respiratory tract?
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Actinobacillus actinomycetemcomitans (AA)
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What damage does Actinobacillus actinomycetemcomitans (AA) do?
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Opportunistic pathogen
Causes endocarditison damaged heart valves and sepsis. |
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Where is AA most commonly implicated?
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With etiology of localized aggressive juvenile periodontitis
periodontitis in juvenile diabetes |
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What bacteria causes root-surface caries?
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Actinomyces viscous and naeslundii
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What are synthesized from dieatary sucrose by cariogenic and plaque bacteria primarily as extracellular polysaccharides?
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Dextrans, mutans, levans
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What has been shown to be the most effective antimicrobial agent for reducing plaque and gingivitis long-term?
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Chlorohexidine
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Why is chlorohexidine considered to be so effective?
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Greatest residual concen. in mouth after use
Rapidly absorbed onto teeth and pellicle Slowly released |
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What is chlorohexidine approved as by the ADA?
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Antimicrobial and Antigingivitis agent
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What are some examples of chlorohexidine?
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Peridex and Periogaurd
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What is the most common side effect of chlorohexidine?
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Temp. superficial staining of oral structures
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What are three other topical antimicrobials besides chlorohexidine?
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Stannous fluoride
Phenolic compounds Quaternary ammonium compounds |
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What is the antimicrobial action in stannous fluride related to?
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Stannous tin ion instead of fluoride ion
(Gel Form) |
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What does the ADA accept stannous fluoride for?
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Anticaries
NOT - Antiplaque or antigingivitis |
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What are phenolic compounds approved for by the ADA?
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Antimicrobial / antigingivitis
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What is an example of a phenolic compound ?
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Listerine
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What compound seems to be not as effective as others in reducing plaque or gingivitis, but seems very effective at eliminating bad breath (halitosis)?
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Quaternary ammonium compounds
(scope / cepacol) |
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Which specific bacteria species have been implicated in the dental caries process?
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Streptococcus
S. Mutans S. Sanguis S. Salivarius |
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What is the most frequently isolated streptococcus in the oral cavity?
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S. Sanguis
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What do Steptococcus bacteria do in the mouth?
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Produce detran sucrose that catalyzes formation of extracellular glucans from dietary sucrose.
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What is another name for dextran sucrose?
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glucosyltransferase
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What does glucan production contribute to?
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Formation of dental plaque
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What does dental plaque hold that is produced by streptococci against the tooth?
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Lactic acid
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What does lactic acid dissolve on the tooth?
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Hydroxyapatite crystals
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What is the major cariogenic property of S. mutans?
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Production of enzyme
glucosyltransferase |
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What are the essential properties that are necessary for caries formation?
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Adhere to tooth
Lactic acid production Produce polymeric substance that causes acid to remain in contact with the tooth |
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What are the prerequisites for development of caries?
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Cariogenic bacteria
Susceptible host Supply of substrate for lactic acid production |
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What is the principal site for the growth of gram negative anaerobes like spirochetes, and fusobacteria?
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Gingival sulcus
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Why is the gingival sulcus susceptible to these bacteria?
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1. Increase crevicular (gingival) fluid
2. Desquamation of epithelial cells 3. Bacterial acid products |
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What kinds of bacteria does a normal healthy mouth consist of?
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Obligate / Facultative anaerobes
Acidogenic bacteria |
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True False:
The influenceing bacteria for periodontal disease is the same bacteria that is normally present in a healthy mouth. |
True
these bacteria become opportunistic |
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What bacteria produces hydrogen peroxide?
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S. Sanguis
S. Mitis |
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What bacteria is aciduric and produces lactic acid?
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S. Mutans
Lactobacillus casei |
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What bacteria is found consistently in saliva and on oral soft tissue?
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S. Salivarius
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What are the most numerous group of bacteria in the oral cavity, are gram positive cocci and are facultative anaerobes?
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Streptococci
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What is the percentage of plaque components?
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Water (80%)
Solids (20%) - 95% of this is bac. |
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What are the stages of plaque formation?
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1. Formation of the pellicle
2. Bacterial colonization 3. Maturation Stage |
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Surface coating of salivary origin, which is primarily protein in nature, with some carbohydrate complexes. Essentially structureless and bacteria-free. Forms on clean teeth within minutes.
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Acquired pellicle
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Why does the pellicle form within minutes on a clean tooth surface?
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Due to its salivary origin
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What surfaces will the acquired pellicle form on?
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Tooth
Crowns Dentures Porcelain teeth |
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What is the order of bacteria deposition on the tooth during the bacterial colonization phase of plaque?
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Orderly
1. Streptococci (gram positive) Large amounts 2. Rod shaped microorganisms (Bacteroides and fusobacterium) Attach and colonize 3. Mature plaque cause morph shift to filamentous bac. (actinomyces) |
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Saliva contnues to provide agglutinating substances and other proteins to the intercellular matrix, and bacterial intercellular adhesion results. The crystalline structure will increase and eventually calcify. (calculus)
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Maturation Stage of pellicle formation
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What is young plaque dominated by?
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gram-positive cocci
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What is usually one of the first colonizers of plaque?
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Streptococcus sanguis
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What is the percentage of gram positive cocci in young plaque?
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40-50% streptococcus
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What is the percentage of gram positive rods in young plaque?
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10-40% lactobacillus
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What is the percentage of gram negative rods in young plaque?
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10-15% Fusobacterium
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What is the percentage of filaments in young plaque?
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4% or less
Actinomyces and Veillonella |
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What changes occurs when plaque ages?
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50% gram + and 30% gram -
# cocci decrease / # filaments increase Aerobic bac. decrease / Anaerobic bac. increase |
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How long does it take for calculus to mineralize both sub and supra gingivally?
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12 days
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What are the inorganic components of calculus?
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70-90%
Calcium and phosphate Small amount magnesium / carbonate (from saliva) Hydroxyapatite / Fluoride |
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What are the organic components of calculus?
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Microorganisms (same as plaque)
Desquamated epithelial cells leukocytes mucin |
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How is calculus mineralized?
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Bathing in saliva giving it calcium and phosphorus
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Why is subcalculus dark?
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Due to pigments from blood break down
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Which has more anaerobes?
Supra- or sub- gingival plaque? |
Subgingival
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What alters bacterial composition?
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Saliva and diet
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What are the main characteristics of supragingival plaque?
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- Attached or tooth associated
- Gram + anaerobic cocci - As ages vibrios, spirochetes and gram neg. bact. predominate |
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What are the bact. that are associated with supragingival plaque?
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S. Sanguis, actinomyces viscosus, naeslundii
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What are the main characteristics of subgingival plaque?
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- Lossely attached (epi. associated)
- gram neg. anaerobic rods |
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What are the bact. associated with subgingival calculus?
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Actinomyces
Fusobacterium nucleatum Treponema (spirochetes Veillonella |
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The progression from a healthy gingival sulcus to gingivitis is associated with a shift towards what?
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gram-negative bacteria
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What bacteria is commonly implicated in the etiology of acute necrotizing ulcerative gingivitis?
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Prevotella intermedia
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Condition which presents rather pathognomonic (characteristic of a single disease) within the oral gingiva.
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ANUG
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What are the clinical signs of ANUG?
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(Important)
Interproximal necrosis History of soreness and bleeding gums (Less Important) fetor oris (offensive odor) low-grade fever lymphadenopathy malaise |
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What is the dominant WBC in the inflammatory infiltrate of ANUG?
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neutrophil
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When does ANUG most often occur?
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Adults between 18-30
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What are factors which offer a predisposition of ANUG?
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Gingivitis
Tobacco smoking gross neglect (bad hygiene) fatigue stress |
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What are all of the bacteria associated with ANUG?
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Intermediate sized spirochetes
Prevotella intermedia Fusobacterium species Selenomonas species |