Salivary Pellicle Flashcards
what does the oral microbial ecology dept on
saliva
lifestyle
microflor
host defences
what happens to K at rest and tim and GCF
80
80
70
what is Ca at rest stem nd GCF
6
6
20
is there bicarbonate in GCF
no
what is mg/100ml bicarb tim and rest
200
31
what are some salivary functions
Digestion buffer mineralisation librication/visc tissue coat anti fungal anti viral anti bac
what is the digestion function
amylases
mucins
lipases
what is the mineralisation function
cystatins
histamines
PRP
statheirns
what is the anti fungal function
histatines
what si the tissue coating function
amylases cystatins mucins PRP statherins
what si the anti viral fuction
cystatins
mucins
what si the anti bac fucntion
amylases cystatins histatines mucins peroxides
what is the buffering fucntion
carbonic anhydrase
histatins
what si the formation of the acquired pellicle
material depo rapid on fresh clean tooth
peptides proteins enzymes glycoproteins lipids glycolipids
how thick is pellicle
0.1-1um
what si the pellicle simple
cell free proteinaceous layer
what si selective adsorption of pellicle
of hydroxyapatite reactive salivary proteins, serum proteins and microbial products
- contains most salivary proteins and lipid
wat is the diffusion barrier of pellicle
protects agains bac acids
slows loss of dissolved calcium and phosphate ions
what is the renewable lubricant of the pellicle
helps protect teeth from a attrition and abrasion
what are the ions at the enamel surface
cations - Ca
anions - hydroxide and phosphate
what si the net charge of the enamel surface
-ve
what does contact with saliva and the enamel surface immediatelyproduce
charged layer
- hydration/ stern layer
counter ions calcium
pellicle formation on ….. discs
HA
is HA sol
not very much
what is the basic HA make up
saliva supersaturated for salts
loss of calcium phosphate depends on amount of
Ca
PO4
2OH in solution
mass action of calcium phosphate is at
equilibrium
at a low pH what happens to supersaturation
it decreases
CRITICAL pH
what is supersaturation
high pH CaPo4 can precip
need nuc sites
pellicle mask underly HA prevent nuc site
plaque - nuc site
what is carbonic anhydrase unique to
saliva
what reaction does carbonic anhydrase drive
bicarbonate and hydrogen –> carbon dioxide and water
what si the phase buffering of Carbonic Anhydrase
phase conversion of dissolved CO2 into a volatile gas
contributes to neut acids
what secretes CA IV
acinar cells as isoenzyme
what does CA IV do when sec
binds to pellicle
localised protection though removal of hydrogen ion
what is a statherin
acidic phosphoprotein
4 variants present
where do statherins concentrate
at air/saliva interface along with calcium
what do staherins prevent
primary and secondary calcium phosphate disposition
what are the components of a statheirn
n terminal basic residue
NMR helical structure
whats the acton of statherni
occupy site that would otherwise be used for nucleating crystallisation
what are PRP
fam proteins
rich proline, glutamic acid, glutamine and glycine
amphiphilic
what are the 3 groups of PRPs
acidic
basic
glycosylated
what is a key theme of proline
flexible
can have conformational changes dept on fucntion
PRPs can proteolytically cleave - what does this mean
oral fluid and glandular see distinct
sterile to non sterile
expo to bac derived proteases
release peptides when broken down
when do PRP bind
early binding to pellicle and incorp into mature biofilms
what does the N terminus of PRP similar to
stathern
where is PRP said to be
occupy sites where calcium phosphate depo would occur
what are some calcium phosphate inhibitors
stratheirn
acidic PRP
what are moderate inhibit of CaPhos
histatins
cystatins
what are some weak inhibit of CaPhos
mucins
amylase
the surface layer of early carious lesion forms what
impermeable barrier to diffusion of high m.w inhibitors
still per to Ca and Phos
inhibitors may encourage what
mineralisation by preventing crystal growth on surface of lesion by keeping pores open
inhibitors can form complexes that release
calcium d phsoate ions
what is the most abundant salivary enzyme
alpha amylase
what does alpha amylase do
hydrolyse glycosidic bonds of polysaccharides
what si the end product of amylase
maltose – further fermented to glucose by oral bac
what is alpha amylase resistant to
proteolytic cleavage
when is alpha amylase immobilised on pellicle
in assc with mucin or antibodies
what is secreted by von ebner glands of tongue
lingual lipase
serous hands around circumvallate pap
what is lipase involved in
fat digestion hydrolyse med to long chain triglycerides digest milk fat highly hydrophobic remains active in stomach
what do salivary glycoproteins contribute to the pellicle
90% of acquired pellicle
26% salivary proteins
what does salivary glycoproteins cotain
acidic sugars -ve (sialic acid)
what is a key factor os salivary gycoprotiens
reduce surface tension
what si the tissue coating function assc with mucin
protective covering about hard/soft tissues
primary role in formation of acquired pellicle
what si the lubrication function assc with mucin
align with direction flow
increases lubricating qualities
what ar he roles of mucins
mem assi mucin
secreted mucins
gel filtration effect
ion exchange effects
what are the two major ours of salivary mucin
MG1 - oligomeric mucin glycoprotein
MG2 - monomeric mucin glycoprotein
what is MG1
mix of 2 mucins
GEL FORMING
mem bound
mucosal ad enamel surface coating
what is MG2
one gene product
influence on oral microbiota
what is H2o2
highly reactive oxygen sp
what is estimated levels of h2o2 in whole saliva
8-14 uM
what si the major source of h2o2
facultative anaerobes
- s sanguines
- s mitis
what can h2o2 be covered to and cause what
cons to hydroxyl radicals
damage to DNA and lipids
dismutaion of h2o2 critical for
protecting mucosa, fibroblasts etc
what can be used for dismutaion of h2o2
bacterial catalases
salivary peroxides
what is sialoperoxidase secreted by
parotid ad submandibular glands
what happens to sialoperoxidase
readily adsorbed t various surfaces of mouth
what is myeloperoxidases form
leukocytes entering Gingival crevice
what does the amount of peroxides depend on
the extent of inflamed sites in perio and mucosal surfaces
what do the peroxides essentially do
protects host from h2o2 toxicity
gen antimicrobial end products
what is the oxidase many present when there is h2o2
thiocyanate
what is thiocyanate
electron donor
normal component of saliva
salivary concentration dept on diet and smoke
