Chapter 3 Flashcards
risk factors for periodontal disease
- 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
what are local factors
- environmental
what are systemic factors
- medical conditions
what are host factors
- own body
- susceptibility of disease
what is inflammatory periodontal disease the result of
- accumulation of dental plaque (microorganisms are part of the plaque)
what is microbial biofilm
- gelatinous matrix-enclosed bacterial populations
- bacteria adhere
- must disrupt biofilm
what is extracellular matrix
- protects from external sources such as antibiotics/antimicrobials
how many different species of bacteria are present in oral biofilms and how many are pathogenic
- more than 700 bacterial species in oral biofilm
- less than 10% are pathogenic
what type of morphology of bacteria are there in oral biofilms
- wide variety of shapes
- aerobic vs nonaerobic
- motile vs nonmotile
- gram + vs gram -
- saachrolytic vs asaachrolytic (capable or non capable of metabolizing sugar)
describe bacteria present in healthy mouths
- gram-positive
- aerobic
- nonmotile
- saachrolytic
describe bacteria present in diseased mouths
- gram-negative
- anaerobic
- motile
- asaachrolytic
2 types of bacteria found in health
- streptococcus species
- actinomyces species
3 main types of bacteria associated with periodontal disease
- AA (stages I-IV)
- PG (stages I-IV)
- Tannerella forsynthesis (stages I-IV) not as important as the other 2
what is acquired pellicle
- first few hours after laid down contains proteins and glycoproteins
- saliva and crevicular fluid
- provides specific receptors for bacterial attachment
what are adhesions
- bacterial adherence to surface proteins
when is phase I/initiation for oral biofilms formation and what is it
- 1-2 days
- individual clones and layers
- gram + cocci
- streptococcus mutans
when is phase II for oral biofilms formation and what is it
- 2-4 days
- gram + rods
- gram - cocci
- some anaerobes: anaerobic environment between layers
when is phase III for oral biofilms formation and what is it
- 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
what are sub gingival biofilms
- live as strict or obligate anaerobes (can’t live with O2)
- multiplication - increasing thickness
what are the 3 types of sub gingival bacterial biofilms
- 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)
what are tooth associated bacteria
- gram + facultative aerobes
- removed by scaling and root planing
- less virulent
what are tissue associated bacteria
- gram -, anaerobic, motile
- not removed by scaling or root planing
- more virulent
what are unattached bacteria
- gram -, anaerobic, motile
- removed by flushing
- more virulent
how do subgingival biofilms get their nutrients
- provided by gingival crevicular fluid
- compounds in GCF enhance the growth of porphyromonas and prevotella species
- antimicrobial properties (immunoglobulins) prevents bacteremia and infections
what happens during bacterial tissue invasion
- subgingival AA, PG and spirochetes invade into the lamina propria
- cannot eliminate with scaling
- contributes to aggressive periodontitis
microorganisms in dental implants
- same as with teeth
- important not to scratch implants as this will cause more sport for bacteria to attach
components of plaque (biofilms)
- bacteria
- cells: epithelial white and red blood cells, ghost cells, all filled with bacteria
what are tooth accumulated materials (TAMs)
- loosely adhere
- no major impact on perio
- mostly food bacterial mixture (like materia alba)
3 types of mechanisms of bacterial action: direct effect
- cytotoxic agents (endotoxins)
- enzymes
- host derived enzymes
what are cytotoxic agents
- 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
what are enzymes
- produced and released by subgingival bacteria within the periodontal pocket
- destroys connective tissue: collagen, ground substance
- matrix metalloproteinases (MMPs) (host derived), collagenases
what are host derived enzymes
- same or very similar to bacterial enzymes
- matrix metalloproteinases (MMPs); collagenases, gelatinases, common enzymes that break down periodontal tissues
what are immunopathologic mechanisms
- indirect mechanisms of bacterial action
- bacterial antigens stimulate inflammatory response
- destructive as well as protective
