Chapter 3

Question 1

risk factors for periodontal disease

Answer 1

• poor oral hygiene
• tobacco smoking
• genetics/heredity
• advanced aging
• stress
• past history of perio
• systemic disease
• male gender
• compromised host defense
• race, ethnicity
• regularity of dental care
• interleukin-1 production

Question 2

what are local factors

Answer 2

• environmental

Question 3

what are systemic factors

Answer 3

• medical conditions

Question 4

what are host factors

Answer 4

• own body

- susceptibility of disease

Question 5

what is inflammatory periodontal disease the result of

Answer 5

• accumulation of dental plaque (microorganisms are part of the plaque)

Question 6

what is microbial biofilm

Answer 6

• gelatinous matrix-enclosed bacterial populations
• bacteria adhere
• must disrupt biofilm

Question 7

what is extracellular matrix

Answer 7

• protects from external sources such as antibiotics/antimicrobials

Question 8

how many different species of bacteria are present in oral biofilms and how many are pathogenic

Answer 8

• more than 700 bacterial species in oral biofilm

- less than 10% are pathogenic

Question 9

what type of morphology of bacteria are there in oral biofilms

Answer 9

• wide variety of shapes
• aerobic vs nonaerobic
• motile vs nonmotile
• gram + vs gram -
• saachrolytic vs asaachrolytic (capable or non capable of metabolizing sugar)

Question 10

describe bacteria present in healthy mouths

Answer 10

• gram-positive
• aerobic
• nonmotile
• saachrolytic

Question 11

describe bacteria present in diseased mouths

Answer 11

• gram-negative
• anaerobic
• motile
• asaachrolytic

Question 12

2 types of bacteria found in health

Answer 12

• streptococcus species

- actinomyces species

Question 13

3 main types of bacteria associated with periodontal disease

Answer 13

• AA (stages I-IV)
• PG (stages I-IV)
• Tannerella forsynthesis (stages I-IV) not as important as the other 2

Question 14

what is acquired pellicle

Answer 14

• first few hours after laid down contains proteins and glycoproteins
• saliva and crevicular fluid
• provides specific receptors for bacterial attachment

Question 15

what are adhesions

Answer 15

• bacterial adherence to surface proteins

Question 16

when is phase I/initiation for oral biofilms formation and what is it

Answer 16

• 1-2 days
• individual clones and layers
• gram + cocci
• streptococcus mutans

Question 17

when is phase II for oral biofilms formation and what is it

Answer 17

• 2-4 days
• gram + rods
• gram - cocci
• some anaerobes: anaerobic environment between layers

Question 18

when is phase III for oral biofilms formation and what is it

Answer 18

• 4-7 days, 7-11 days
• plaque thickens coronally
• more filamentous bacteria (spirochetes and gram negative rods)
• new plaque layer on top
• PMNs (neutrophils) in gingival crevicular fluid
  after 7-11 days
• gingival enlargement, clinical gingivitis
• spirochetes multiply
• increase in anaerobic and gram -
• move subgingival

Question 19

what are sub gingival biofilms

Answer 19

• live as strict or obligate anaerobes (can’t live with O2)

- multiplication - increasing thickness

Question 20

what are the 3 types of sub gingival bacterial biofilms

Answer 20

• tooth associated (attached)
• tissue associated (attach to tissue increase swelling, causing more room to descend and penetrate and grow)
• unattached (mobile organisms that are unattached producing toxins, enzymes causing damage)

Question 21

what are tooth associated bacteria

Answer 21

• gram + facultative aerobes
• removed by scaling and root planing
• less virulent

Question 22

what are tissue associated bacteria

Answer 22

• gram -, anaerobic, motile
• not removed by scaling or root planing
• more virulent

Question 23

what are unattached bacteria

Answer 23

• gram -, anaerobic, motile
• removed by flushing
• more virulent

Question 24

how do subgingival biofilms get their nutrients

Answer 24

• provided by gingival crevicular fluid
• compounds in GCF enhance the growth of porphyromonas and prevotella species
• antimicrobial properties (immunoglobulins) prevents bacteremia and infections

Question 25

what happens during bacterial tissue invasion

Answer 25

• subgingival AA, PG and spirochetes invade into the lamina propria
• cannot eliminate with scaling
• contributes to aggressive periodontitis

Question 26

microorganisms in dental implants

Answer 26

• same as with teeth

- important not to scratch implants as this will cause more sport for bacteria to attach

Question 27

components of plaque (biofilms)

Answer 27

• bacteria

- cells: epithelial white and red blood cells, ghost cells, all filled with bacteria

Question 28

what are tooth accumulated materials (TAMs)

Answer 28

• loosely adhere
• no major impact on perio
• mostly food bacterial mixture (like materia alba)

Question 29

3 types of mechanisms of bacterial action: direct effect

Answer 29

1. cytotoxic agents (endotoxins)
2. enzymes
3. host derived enzymes

Question 30

what are cytotoxic agents

Answer 30

• lipooligosaccharide (LOS)
• previously termed lipolysaccharide
• gram - found in cell wall
• toxins released when cells die
• initiates inflammation and bone destruction
• LOS found in root cemetum

Question 31

what are enzymes

Answer 31

• produced and released by subgingival bacteria within the periodontal pocket
• destroys connective tissue: collagen, ground substance
• matrix metalloproteinases (MMPs) (host derived), collagenases

Question 32

what are host derived enzymes

Answer 32

• same or very similar to bacterial enzymes

- matrix metalloproteinases (MMPs); collagenases, gelatinases, common enzymes that break down periodontal tissues

Question 33

what are immunopathologic mechanisms

Answer 33

• indirect mechanisms of bacterial action
• bacterial antigens stimulate inflammatory response
• destructive as well as protective