MDS PREP
How does the concentration of mercury in urine relate to neurological changes?
1) Neurological changes are detected at urine mercury levels of 1 µg/L.
2) Neurological changes are detected at urine mercury levels of 10 µg/L.
3) Neurological changes are detected at urine mercury levels of 500 µg/L.
4) There is no established link between mercury concentration in urine and neurological changes.
Neurological changes are not detected until urine mercury levels exceed 500 µg/L, which is significantly higher than the levels associated with amalgam placement.
Type of investment material used for casting of removable partial denture with base metal alloy
1) Gypsum based material
2) Phosphate based material
3) Ethyl silicate bonded
4) All of the above
What are the three physical properties controlled by the ANSUADA Specification No. 1 (ISO 24234) for dental amalgam?
1) Creep, tensile strength, and thermal expansion.
2) Compressive strength, hardness, and density.
3) Creep, compressive strength, and dimensional change.
4) Tensile strength, modulus of elasticity, and corrosion resistance.
The specification controls the qualities of dental amalgam by listing requirements for creep, compressive strength, and dimensional change.
What is the typical force applied during the condensation of a 0.5 mm diameter condenser nib?
1) 0.04-0.4 µm
2) 1-5 µm
3) 3.75 pounds
4) 8.43 pounds
The recommended force for condensing a composite resin using a 0.5 mm diameter condenser nib is 3.75 pounds. This is the force that is well within the physiologic limits of the tooth and provides effective condensation.
What is the maximum allowable level of mercury in the blood?
1) 0.5 µg/L
2) 3 µg/L
3) 5 µg/L
4) 10 µg/L
The maximum allowable level of mercury in the blood is 3 µg/L according to the given text.
What is the structural formula of the substance found in irreversible hydrocolloid?
1) Anhydro-?-d-mannuronic acid
2) Anhydro-?-d-glucuronic acid
3) Anhydro-?-d-glucuronic acid
4) Anhydro-?-d-mannuronic acid
Irreversible hydrocolloid, such as alginate, is based on the structure of anhydro-?-d-mannuronic acid.
What is the Threshold Limit Value (TLV) for mercury vapor exposure set by OSHA?
1) 0.01 mg/m3
2) 0.02 mg/m3
3) 0.05 mg/m3
4) 0.1 mg/m3
The TLV for mercury vapor set by OSHA is 0.05 mg/m3.
How does the degree of polymerization affect the strength of resin?
1) There is no correlation between the two
2) Higher degree of polymerization results in increased strength
3) Lower degree of polymerization results in increased strength
4) The strength is unaffected by the degree of polymerization
A higher degree of polymerization in resins generally correlates with greater strength, as more polymer chains are formed and cross-linked.