biochem 7B mineralization Flashcards
what area of the tooth does not demonstrate mienralization
pulp
what are the hardest tissues of the tooth
enamel and dentin
hardness in biologyical systems is related to what
the ability to form calcium salts
mineral in the teeth is what and what is the formula
hydroxyapatite
Ca10(PO4)6(OH2)
it is a dimer
dentin breakdown
70% mineral, 30% protein
enamel breakdown
97% mineral, less than 1% protein
enamel is formed on extracellular matrix involving what organizing proteins by what
organizing proteins - enamelins and amelogenins
by ameloblasts
what are ameloblasts
cells which secrete the enamel protein enamelin and amelogenin which will later mineralize to form enamel on teeth, the hardest substance in the human body
when are ameloblasts present
only during tooth development
where is dentin formed and how is it form
formed by odontoblasts
formed around the pulp on an extracellular matrix of collagen and non-collagenous proteins
what are apatities
phosphorylated minerals that typically contain calcium
what is the most common apatite
hydroxyapatite Ca10(PO4)OH2
when OH is replaced by fluoride in hydroxyapatite what does it become
fluoroapatite
Ca10(PO4)6(F2)
calcium phosphates (hydroxyapatite) is very insoluable or soluable
highly insoluable
what is nucleation and when does it occur
nucleation - when theres the right environemnt (includes scaffolding proteins) and right factors (high concentration of ions) mineral will form
what mineralizes dentin and what scaffolding protein does it need
odontoblasts, collagen
what minearlizes enamel and what scaffolding proteins does it need
ameloblasts, amelogenins
what is exuded by odontoblasts which line the pulp cavity purgest the enaml of bacterial waste
dentinal fluid
primary function of dental pulp is what
to form dentin (by the odontoblasts)
saliva is supersaturated with what ions and buffers around what pH
calcium and phosphate ions, around pH7
what are the bacterial waste products
-bacteria metabolizing aerobically excude CO2 and H2O
-bacteria metabolizing anaerobically excude acids (lactic acid)
enamel beings to dissolve and dimineralize at what pH
5.5
what in the saliva helps resist the loss of mienral
calcium and phosphate
what helps neutralize acid and wash out waste
fluid flowing from the pulp
what stabilizes crystallites
anionic proline-rich proteins and statherin
what does aniomic proline rich proteins do
bind to calcium
what does statherin do
maintains high calcium level in saliva, which prevents teeth from dissolving
what does saliva do to pH
neutralizes H+
adding fluoride forms what
fluorapatite
fluorapatite is insoluable or soluable and how does it compare to fluorapatite
insoluable
fluorapatite is severla times less soluable
is fluorapatite more or less resistant to demineralization by acid than hydroxypatite
more resistant to demineralization by acid
how does fluoride help
inhibit bacterial metabolism lowering acid excretion by plaque bacteria
what amound of fluoride in water is optimal for cavity protection
1 ppm
greater the floride, greater the index of what
fluorosis (white or brown specs on ur teeth)
8-10ppm
is fluoroapatite more resistant or less resistant to demineralization by acid than hydroxapatite
more resistant
what happens in fluoride poisoning
associated w lack of energy due to its inhibiting enolase and therefore glycolysis
if flouride is taken at high levels to control osteoporosis, what is the result and does it inhibit osteoblast or osteoclast more
inhibits osteoblast activity more than osteoclast activity, resulting in an increased frequency of bone fractures
flouride inhibits what at 50-100ppm and how
inhibits gluconeogenesis by binding to Mg2+ ions that activity fructose 1,6 diphosphate
inhibits ROS elimination by binding iron, selenium and molybdenum at catalytic centers of catalase, peroxidase, and superoxide dismutase
