35 - anti-plaque and caries drugs Flashcards
tooth
The _ is held together by a boatload of weak interactions. However, there will always be some Ca2+ and some PO4 3- dissolving into the saliva and some Ca2+ and some PO4 3- (from the saliva) adding back to the enamel.
hydroxyapatite
The loss of Ca2+ and PO4
3- is referred to as demineralization.
The addition of Ca2+ and PO4
3- is referred to as
remineralization.
Acid is bad for tooth enamel because it enhances
_ and inhibits _.
enhances
demineralization and inhibits remineralization.
Weakens interactions of tooth structure and Makes it easier
for Ca and PO4 to
leave
Acid inhibits remineralization
Phosphate is a base, and pH will affect the distribution of
it’s ionic forms
_ form rules at low pH
_ at neutral pH
_ rules at high pH
H3(PO4) at low pH
H2(PO4) - neutral
H(PO4)
PO4 - rules at high pH
Basically, the lower the pH, the less
(PO4)3- will be available. Thus, remineralization is
diminished.
mouth chemistry
the critical pH for demineralization vs remineralization
5.5
below 5.5 - tooth loss Ca and PO4
about 5.5 - tooth gain minerals
_ is the major caries-causing bacterium
Streptococcus mutans
Streptococcus mutans happy in acid environment,
make lots of lactate (decreases pH)
how does Fluoride prevent decay?
_ is the mouth’s primary defense against tooth decay.
Research has
proven that fluoride works to prevent tooth decay by boosting the ability of
saliva to return lost minerals to tooth enamel before cavities can develop.
Saliva enhances protection of enamel by providing high levels of calcium and
phosphate ions at the tooth surface. The presence of those ions slows
demineralization and encourages an ongoing remineralization of tooth
enamel. The best explanation of how fluoride works is that it enhances _.
Saliva primary defense
Fl enhances the
natural remineralizing properties of saliva
If all the _ in a tooth was replaced with fluoride, you would have a tooth with: Smaller crystals Better H bonding within the crystal Decreased solubility
hydroxide
Fluoride in tooth enamel is < 2,000 ppm. Since this amount is effective,
diminished solubility of the enamel doesn’t seem like a good explanation why
fluoride prevents cavities*
Fluoride in solution and/or in the tooth enhances the rate of
remineralization of hydroxyapatite. - this is how it works
When fluoride ions are present in plaque fluid along with dissolved hydroxyapatite, and the pH is
higher than _, a fluorapatite-like remineralised veneer is formed over the remaining surface of the
enamel; this veneer is much more acid-resistant than the original hydroxyapatite, and is formed
more quickly than ordinary remineralised enamel would be. The cavity-prevention effect of fluoride
is partly due to these surface effects, which occur during and after tooth eruption*
4.5
What explanations (that make some sense) have been offered to explain how – F prevents caries ? 2. Fluoride bacteria interactions
Fl can inhibit _, an enzyme in glycolysis
enolase
What other anticaries agents are out there?
Casein Pyrophosphate Amorphous Calcium
Phosphate (CPP-ACP)
does it work?
Seems to work (promotes
remineralization), not clear that
it’s got advantages over fluoride
What other anticaries agents are out there
Arginine-containing (toothpastes, mints etc
Seems to help, maybe
verdict not totally in
What other anticaries agents are out there?
Chlorhexidine vs Triclosan
CHX - Rx, effectiveness
Triclosan
Xylitol - Sweetener, doesn’t break down (no acid). Mixed bag of
data on effectiveness in preventing caries
typically, a healthy person has only about 120 different species in their dental plaque. Interestingly, patients with high risk for dental caries may have more gross amount of plaque but usually have fewer _ Not as many bacteria are adapted to survive in the low pH conditions of the dentalcaries-producing plaque or biofilm.
fewer total species.
because the low pH only lets certain (bad) bacteria survive
healthy gums have _ microbes and _ anaerobes
gram positive microbes
facultative anaerobes
unhealthy gums - gram negative and obligate anaerobes
A few health problems linked to poor _
Heart disease - Bacteria in the bloodstream can travel to the heart and lead
to a heart attack.
Endocarditis- Bacteria may find its way to the inner linings of the heart and
valves which in turn, create growth pockets of bacteria. These pockets cause
inflammation and infection of the inner linings of the heart.
Stroke - There are a number of reasons why a stroke may occur - one of them
is the narrowing of artery walls and another is blood clots. It is believed that
oral bacteria may be a contributing factor to the arteries narrowing as well as
blood clots easily forming because of the body’s negative response to the
bacteria in the bloodstream.
Inflammation - Inflamed gums and bleeding may cause systemic
inflammation.
Rheumatoid Arthritis.
oral hygiene
