Dental Plaque Flashcards
(46 cards)
definition of dental plaque
an organized mass, consisting mainly of MICROORGANISMS EMBEDDED IN A MATRIX OF GLYCOPROTEINS that ADHERES TO TEETH, PROSTHESES, AND ORAL SURFACES which is found in the GINGIVAL CREVICE AND PERIODONTAL POCKETS
definition of biofilm
a MULTI-SPECIES COMMUNITY of micro-organisms that ADHERE to EACH OTHER AND A SURFACE and are ENCASED IN AN EXTRA-CELLULAR MATRIX
environments that biofilm can grow in
minerals and metals underwater underground above ground plant tissues animal tissues implanted medical devices catheters and pacemakers
PERIODICALLY OR CONTINUOUSLY SUFFUSED WITH WATER
fossil evidence of biofilm?
dates back to 3.25 billion years ago in the deep-sea hydrothermal rocks of the pilbara -craton in australia
when does biofilm FORMATION begin
when free-floating micro-organisms come in contact with an appropriate surface
when does biofilm ATTACHMENT begin
when the microorganisms produce an EXTRACELLULAR POLYSACCHARIDE MATRIX (ESP) – which is a network of sugars, proteins, and nucleic acids
when does biofilm GROWTH occur?
when further layer os microorganisms and EPS build upon the first layers
EXTRACELLULAR POLYSACCHARIDE MATRIX definition?
network of sugars, proteins , and nucleic acids which facilitate the attachment of the biofilm
what determines the extent of growth of a biofilm?
the environmental conditions
advantages of microorganisms living in a biofilm?
communities of microbes are usually MORE RESILIENT TO STRESS
what is the composition of dental plaque?
- general percentage breakdown
80% water
20% solid material
- 35% cellular and 65% extracellular
what is the composition of dental plaque?
- microorganisms
- extracellular polysaccharide matrix (organic)
- 95% dextran , 5% levan - bacterial by-products - enzymes food debris, desquamated cells
- calcium and phosphate (inorganic)
breakdown of extracellular polysacharide matrix in dental plaque
95 % dextran
5% levan
structural traits of oral micro-organisms
- cocci
- bacilli
- spirilla
definition of aerobe
a microorganisms that can live and grow in the presence of oxygen
definition of anearobe
faculative?
obligate?
a microorganisms that can live in partial or complete absence of oxygen
faculative – capable of existing under different conditions, either aerobic or anaerobic
obligate – only anaerobic conditions, strictly
describe commensal micro-organisms
most of these exist in our oral cavity in SYMBIOTIC capacity 0 maintaining relationships with the host that are based on MUTUAL BENEFITS
commensal micro-organisms present in oral cavity
- streptococcus
- actinomyces
- veillonella
- fusobacterium
- porphymonas
- prevotella
- treponema
- nisseria
- haemophilis
- eubacteria
- lactobacterium
- capnocytophaga
- eikenella
- leptotrichia
- peptostreptococci
- staphylococcus
how do bacteria communicate?
describe this?
QUORUM SENSIN
- bacteria use this to coordinate gene expression
- SECRETE A SIGNALING MOLECULE - AUTOINDUCER – to regulate gene TRANSCRIPTION as a response
when a bacteria is adhering to a surface .. what does it depend on?
intricate, specific series of INTERACTIONS B/W THE SURFACE TO BE COLONIZED, THE MICROBE, AND AN AMBIENT FLUID MILIEU (environment)
4 main steps in formation
- acquired pellicle
- bacterial ADHESION
- growth of extracellular matrix
- formation of a moroe complex and mature biofilm
nutrition for bacteria in deeper pockets?
major source comes from the periodontal tissues and blood
these bacteria produce enzymes that cause periodontal destruction
primary colonization by who?
facultative anaerobic GRAM POSITIVE COCCI
after primary colonization? 24 hours later?
plaque consists of mainly streptococci : S Sanguis
