Amalgam Selection Flashcards
True or False: Amalgams can cause fractured cusps.
False
True or False: Amalgams often have recurrent caries.
False
True or False: Resin composites last longer than amalgam.
False
True or False: Amalgam can be bonded to teeth
True (really?)
True or False: Amalgam is old, composite is new and therfore better
False, new is not always better
True or False: The ADA supports amalgam for fear of lawsuits.
No evidence/opinion
True or False: The ADA holds the patent for amalgam.
False
True or False: Amalgam is banned in Germany and Sweden.
False
From where do humans get most of their mercury exposure?
fish
Minamata disease was discovered in ____ after industrial wastewater polluted waters and accumulated highly toxic doses of mercury in ____.
Japan
shellfish and fish
What is the amount of Mercury exposure claimed to be released from amalgam fillings, per day?
1.5 to 50 micrograms/day
however, at 50micrograms per day for 3 years, 10% of the filling would be gone…that’s just not the case
True or False: Comparing amalgam to composite, children with amalgam fillings excreted more mercury in urine.
True, but they did not have adverse renal effects because of it
True or False: There is a statistically significant difference in adverse neuropsychological effects in children with amalgam.
False
*it is possible that very small IQ effects cannot be ruled out, however, there could be selection bias
True or False: A retrospective cohort is at the highest level of evidence.
False
True or False: The amalgam cohort study provided sound evidence of an association between amalgam and disease.
False, limited evidence on an association
True or False: Mercury containing fillings placed during pregnancy increased the risk for low-birth weight children.
False
True or False: Numerous clinical studies have shown the improved performance of amalgam over composite for larger restorations.
True
True or False: Amalgam is just as easily colonized by bacteria when compared to composite.
False, less easily colonized
Is high or low copper amalgam better?
High Copper
- low corrosion
- high strength
- low creep
- high longevity
Which phase in the amalgam setting reaction is eliminated by copper?
gamma 2 phase!
-the phase that is responsible for poor physical and chemical properties (corrosion, low strength, etc)
Which phase interlocks grains of Cu-Sn and prevents sliding at grain boundaries?
n-prime
True or False: Spherical amalgam particles results in smooth carving.
True, its “squishy” but shines up nicely if you can handle it properly
True or False: Lathe cut amalgam results in better proximal contacts and fewer overhangs.
True
Admixed or blended particles will handle like ____ alloys.
lathe-cut (easier to condense against)
What is zinc’s purpose in amalgam?
antioxidant (prolong shelf life)
True or False: Permite amalgam (clinic use) contains zinc.
True
Permite contains zinc… which justifies using 40 year old amalgam cartridges in clinic
If amalgam contains zinc, what must be controlled during placement?
MOISTURE
delays setting reaction, zinc containing amalgam should not be used for apicoectomy
What are the three species of mercury exposure in the United States?
Elemental (Hgo),
Inorganic (Hg2+)
Methylmercury
Which species of mercury is contained in fish?
methylmercury
Which fish contain >1ppm of methylmercury?
Shark, Swordfish, King Mackerel, and Tilefish
True or False: Species with characteristically high levels of mercury include shrimp, tilapia, salmon, pollock, and catfish.
False, these fish have low levels
True or False: 25 amalgam surfaces may increase the brain mercury concentration by about 10 µg/kg.
True
Slow setting amalgam has a _____ ratio of mercury to alloy.
High
think of the mercury as being “wet” which means the restoration takes longer to “dry/set” when there’s more Hg
True or False: Lower mercury-to-alloy ratio = faster set.
True
