Preclinical Dental Hygiene Exam 2 Study Guide
UPDATED ACTUAL Questions and CORRECT
Answers
Biofilm : - CORRECT ANSWER a living film—containing a well-organized community of bacteria—that grows
on a surface
Phase 1/Film Coating - CORRECT ANSWER forms within minutes after cleaning: its a tenacious membranous
layer that is amporhous acellular and organic : forms over surface, restoration, and calculus (CAN BE REMOVED WITH
FLOSSING AND BRUSHING)
Phase 2—Initial Attachment to Pellicle - CORRECT ANSWER - Within a few hours after pellicle formation,
bacteria begin to attach to the surface of the pellicle.
- Some bacteria have hair-like attachment structures that enable them to attach rapidly upon contact.
- These hairlike structures are called fimbriae. (CAN BE REMOVED WITH FLOSSING AND BRUSHING)
Phase 3- New Bacteria Join In (Matrix Formation) - CORRECT ANSWER bacteria attached to the tooth
PRODUCE SUBSTANCES that stimulate other free-floating bacteria to join community, extracellular slime layer is
made.
Extracellular Slime Layer (EPS) - - CORRECT ANSWER the attachment of bacteria to the tooth surface stimulates
the bacteria to excrete this slimy, glue-like substance (happens in Stage 3)
Phase 4/ Microbiology formation (biofilm growth) - CORRECT ANSWER the mass and thickness of biofilm
increases, bacteria proliferate and begin to grow away from the tooth surface, bacteria blooms form
Bacteria blooms - CORRECT ANSWER are periods when specific species or group of species grow at rapidly
accelerated rates (starts in stage 4)
Phase 5/ Mature Dental Plaque Biofilm (maturation) - CORRECT ANSWER bacteria cluster to form mushroom-
shaped micro colonies that attach to the tooth surface at a narrow base or detach in single cells of clumps, release
planktonic cells to spread and colonize in other areas of the mouth
microcolonies - CORRECT ANSWER are complex collections of different bacteria linked to one another
acquired pellicle - CORRECT ANSWER composed of a variety of salivary glycoproteins (mucins) and antibodies
Purpose of Acquired Pellicle : - CORRECT ANSWER -Protect the enamel from acids: provides a barrier
-Facilitates bacterial adhesion to tooth surface by altering the charge and engird of the tooth surface
Natures Sticky Tape - CORRECT ANSWER view the acquired pellicle as "double-sided adhesive adheres to the
tooth surface on one side and aides bacteria in attaching to the tooth
Supragingival pellicle - CORRECT ANSWER Clear, translucent, insoluble, and not readily visible until a
disclosing agent has been applied
Subgingival pellicle - CORRECT ANSWER continuous with the supragingival pellicle
can become embedded in the tooth structured
3 Bacteria Associated with Periodontal Disease - CORRECT ANSWER Aggregtibacter actinomycetemcomitans
(Aa) , Tannerella Forsythia (Tf), Porphyromonas (Pg)
Composition Of Biofilm - CORRECT ANSWER 80% Water & 20% Inorganic/Organic Cells
SupraGingival Biofilms - CORRECT ANSWER -Coronal to gingival Margin
-Adheres to acquired pellicle, bacteria and tooth
-Shape & Size - thin in health, thicker in gingivitis
, -Microorganisms - early biofilm - mostly gram positive cocci : older Biofilm - becomes more complex and Gram
Negative
Etiology Of Supragingival Biofilms - CORRECT ANSWER Gingivitis, SupraGingival Calculus and Dental Caries
Subgingival Calculus - CORRECT ANSWER -Apical to gingival margin
-Adheres to tooth, Subgingival pellicle and calculus
-Molded to pocket shape and thicker as pocket come less tight
-Environment conductive to more anaerobic microorganisms - gram negative spirochetes and rods
Etiology of Subgingival Biofilm - CORRECT ANSWER gingivitis, periodontal infections, sub gingival calculus
Innocuous - CORRECT ANSWER not harmful or offensive
Pathogenic or Virulent - - CORRECT ANSWER capable of causing disease
gram postive bacteria - CORRECT ANSWER purple stain: single thick cell membrane associated with healthy
periodontium
Gram negative bacteria - - CORRECT ANSWER red stain : double cell membrane : important role in inflammatory
periodontitis (tissue destruction)
Microorganisms in biofilm that are acid forming bacteria - CORRECT ANSWER -Streptococcus mutans and
streptococcus sobrinus are initially the etiologic agents
-Lactobacilli aid in progression of lesion
-Decreased Saliva Flow (xerostomia) and increased diet of carbohydrates promote growth of bacteria in biofilm
Ph of biofilm - CORRECT ANSWER After intake of sucrose there is a drop in the pH of biofilm (from 7.0 to 5.5)
Probability of development of dental caries or gingivitis - CORRECT ANSWER increases as the number of
microorganisms increases
Day 1-2 - CORRECT ANSWER Gram-Positive cocci, aerobic, streptococcus mutans and streptococcus sanguis
Day 2-4 - CORRECT ANSWER Cocci still dominate, Increasing numbers of gram-positive filamentous forms &
slider rods : grow on cocci layer and replace them - "corn cob" appearance (when bacteria secrete EPS) Dental biofilm
may have matured by 72 hours and is capable of initiating the inflammatory process.
Day 6-10 - CORRECT ANSWER More mixed and mature flora with increase filaments, rods and fusobacteria with
heavy accumulation of Leukocytes, see thickening of biofilm by gingival margin, as it matures more gram-negative
anaerobic spirochetes and vibrios
Day 10-21 - CORRECT ANSWER Gingivitis is clinically evident
supragingival calculus - CORRECT ANSWER Visible- on clinical crown coronal to margin of the gingiva,
moderately hard, white creamy yellow or gray: takes on stains from tobacco, food, tea of coffee
Most frequent sights of supra gingival calculus - - CORRECT ANSWER opposite of the openings of the ducts of
the submandibular and parotid salivary glands
-lingual surface of mand. anterior teeth
-Facials of Max. 1st and 2nd molars
Subgingival calculus - CORRECT ANSWER apical to the gingival margin and extends to bottom of the pocket and
follows contour of soft-tissue attachment, not visible unless tissue is unhealthy and can be deflected with air
UPDATED ACTUAL Questions and CORRECT
Answers
Biofilm : - CORRECT ANSWER a living film—containing a well-organized community of bacteria—that grows
on a surface
Phase 1/Film Coating - CORRECT ANSWER forms within minutes after cleaning: its a tenacious membranous
layer that is amporhous acellular and organic : forms over surface, restoration, and calculus (CAN BE REMOVED WITH
FLOSSING AND BRUSHING)
Phase 2—Initial Attachment to Pellicle - CORRECT ANSWER - Within a few hours after pellicle formation,
bacteria begin to attach to the surface of the pellicle.
- Some bacteria have hair-like attachment structures that enable them to attach rapidly upon contact.
- These hairlike structures are called fimbriae. (CAN BE REMOVED WITH FLOSSING AND BRUSHING)
Phase 3- New Bacteria Join In (Matrix Formation) - CORRECT ANSWER bacteria attached to the tooth
PRODUCE SUBSTANCES that stimulate other free-floating bacteria to join community, extracellular slime layer is
made.
Extracellular Slime Layer (EPS) - - CORRECT ANSWER the attachment of bacteria to the tooth surface stimulates
the bacteria to excrete this slimy, glue-like substance (happens in Stage 3)
Phase 4/ Microbiology formation (biofilm growth) - CORRECT ANSWER the mass and thickness of biofilm
increases, bacteria proliferate and begin to grow away from the tooth surface, bacteria blooms form
Bacteria blooms - CORRECT ANSWER are periods when specific species or group of species grow at rapidly
accelerated rates (starts in stage 4)
Phase 5/ Mature Dental Plaque Biofilm (maturation) - CORRECT ANSWER bacteria cluster to form mushroom-
shaped micro colonies that attach to the tooth surface at a narrow base or detach in single cells of clumps, release
planktonic cells to spread and colonize in other areas of the mouth
microcolonies - CORRECT ANSWER are complex collections of different bacteria linked to one another
acquired pellicle - CORRECT ANSWER composed of a variety of salivary glycoproteins (mucins) and antibodies
Purpose of Acquired Pellicle : - CORRECT ANSWER -Protect the enamel from acids: provides a barrier
-Facilitates bacterial adhesion to tooth surface by altering the charge and engird of the tooth surface
Natures Sticky Tape - CORRECT ANSWER view the acquired pellicle as "double-sided adhesive adheres to the
tooth surface on one side and aides bacteria in attaching to the tooth
Supragingival pellicle - CORRECT ANSWER Clear, translucent, insoluble, and not readily visible until a
disclosing agent has been applied
Subgingival pellicle - CORRECT ANSWER continuous with the supragingival pellicle
can become embedded in the tooth structured
3 Bacteria Associated with Periodontal Disease - CORRECT ANSWER Aggregtibacter actinomycetemcomitans
(Aa) , Tannerella Forsythia (Tf), Porphyromonas (Pg)
Composition Of Biofilm - CORRECT ANSWER 80% Water & 20% Inorganic/Organic Cells
SupraGingival Biofilms - CORRECT ANSWER -Coronal to gingival Margin
-Adheres to acquired pellicle, bacteria and tooth
-Shape & Size - thin in health, thicker in gingivitis
, -Microorganisms - early biofilm - mostly gram positive cocci : older Biofilm - becomes more complex and Gram
Negative
Etiology Of Supragingival Biofilms - CORRECT ANSWER Gingivitis, SupraGingival Calculus and Dental Caries
Subgingival Calculus - CORRECT ANSWER -Apical to gingival margin
-Adheres to tooth, Subgingival pellicle and calculus
-Molded to pocket shape and thicker as pocket come less tight
-Environment conductive to more anaerobic microorganisms - gram negative spirochetes and rods
Etiology of Subgingival Biofilm - CORRECT ANSWER gingivitis, periodontal infections, sub gingival calculus
Innocuous - CORRECT ANSWER not harmful or offensive
Pathogenic or Virulent - - CORRECT ANSWER capable of causing disease
gram postive bacteria - CORRECT ANSWER purple stain: single thick cell membrane associated with healthy
periodontium
Gram negative bacteria - - CORRECT ANSWER red stain : double cell membrane : important role in inflammatory
periodontitis (tissue destruction)
Microorganisms in biofilm that are acid forming bacteria - CORRECT ANSWER -Streptococcus mutans and
streptococcus sobrinus are initially the etiologic agents
-Lactobacilli aid in progression of lesion
-Decreased Saliva Flow (xerostomia) and increased diet of carbohydrates promote growth of bacteria in biofilm
Ph of biofilm - CORRECT ANSWER After intake of sucrose there is a drop in the pH of biofilm (from 7.0 to 5.5)
Probability of development of dental caries or gingivitis - CORRECT ANSWER increases as the number of
microorganisms increases
Day 1-2 - CORRECT ANSWER Gram-Positive cocci, aerobic, streptococcus mutans and streptococcus sanguis
Day 2-4 - CORRECT ANSWER Cocci still dominate, Increasing numbers of gram-positive filamentous forms &
slider rods : grow on cocci layer and replace them - "corn cob" appearance (when bacteria secrete EPS) Dental biofilm
may have matured by 72 hours and is capable of initiating the inflammatory process.
Day 6-10 - CORRECT ANSWER More mixed and mature flora with increase filaments, rods and fusobacteria with
heavy accumulation of Leukocytes, see thickening of biofilm by gingival margin, as it matures more gram-negative
anaerobic spirochetes and vibrios
Day 10-21 - CORRECT ANSWER Gingivitis is clinically evident
supragingival calculus - CORRECT ANSWER Visible- on clinical crown coronal to margin of the gingiva,
moderately hard, white creamy yellow or gray: takes on stains from tobacco, food, tea of coffee
Most frequent sights of supra gingival calculus - - CORRECT ANSWER opposite of the openings of the ducts of
the submandibular and parotid salivary glands
-lingual surface of mand. anterior teeth
-Facials of Max. 1st and 2nd molars
Subgingival calculus - CORRECT ANSWER apical to the gingival margin and extends to bottom of the pocket and
follows contour of soft-tissue attachment, not visible unless tissue is unhealthy and can be deflected with air
