Factors affecting initiation and progression of lesions Flashcards
what is the first needed phase fro plaque formation
a biofilm
what is a biofilm
community of microorganism attached to a surface work together commensal vary at sire use extra cell material
what is meant by commensal
normal bac but in given circumstances - can cause disease
what is the sequence of events for a susceptible tooth
pellicle formation
bacterial colonisation
microoclony formation
what is needed in pellicle formation
acelular
proteinaceous film derived from saliva
where is the bac in stagnation
0-4 hours
s sanguines s oralis s mitis actnomyces gm -ve bac mutans strep
how long for micro colony form
4-24 hours
where are some common areas of plaque stagnation
gingival recession - root caries
adjacent to partial dentures
what is it called the changing of oral micrfloa from streptococci to acitnomyces
microbial succession 1-14 days
what does acidogenic mean
transport sugars in diet nd convert to acid lactic acid
what does acidic mean
thine in low pH
what si the specific plaque hypothesis
approx 300 species of intra oral microorganisms
sp limited number involved in carious process
immunise against
what is non specific plaque hypothesis
caries results from the over all activity of the micro organisms within the biofilm
all plaque to be removed
what is ecological plaque hypothesis
plaque can accumulate at all tooth sites
balance microflora change dept on local enviro
acidurici and acidogenic
remove plaque from susceptible sites
what does the stephen curve measure
cariogenicty
pH with sucrose intake
from demin to lesion arrest what is shown
improved OH
fluoride
decrease sugar intake
what lesion arrest from demin
uptake sugar intake
poor oral hygiene
no topical floride
what are the two zones of dentine caries
outer an dinner zones
what is the outer zone
outer
demin, denatured, infected and not remin
what is the inner zone
dentine demin, minimally infected, collagen fibres intact and dentine remix
what is challenging th biofilm within use
fissure sealants
ultraconservative caries removal
stepwise excavation
hall technique
what is the first visit of stews excavation
remove only superficial later of infected necrotic dentine
ensure peripheral caries removal complete
place CaOH lining and glass ionomer
leave 6-12 months
what is done in the second visit of stepwise excavation
re celan cavity and restore
what was seen in the first visit
all sites after first excavation were soft, wet, pale and heavily infected
what is seen in secondary visited stepwise
all harder dry dark and reduction in level of infection
what is the microbiology using this techs
decrease microbial load
reduction in microbial diversity
reduction in nutrient amount and complexity fro pulp
