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.
What are the primary advantages of Ormocers over conventional composites?
1) Outstanding biocompatibility and minimal shrinkage.
2) High elasticity and superior resistance to masticatory forces.
3) Enhanced wear resistance and fluoride release.
4) All of the above.
Ormocers offer several advantages over conventional composites. They have excellent biocompatibility, minimal shrinkage, and their chemical structure allows for high resistance to masticatory forces. Additionally, they are aesthetically pleasing and can be polished to resemble natural teeth.
What is the function of ZnO in Gutta Percha?
1) To increase flexibility
2) To improve thermal insulation
3) To enhance radio-opaque properties
4) To form the matrix of Gutta Percha
ZnO is a filler in Gutta Percha, and it improves the strength and flexibility of the material.
What is the classification of amalgam alloys based on zinc content?
1) Alloys with more than 0.01% zinc are classified as zinc-free, and those with less than 0.01% as zinc-containing.
2) Alloys with more than 0.01% zinc are classified as zinc-containing, and those with less than 0.01% as uno-zinc.
3) Alloys with more than 0.01% zinc are classified as high-zinc, and those with less than 0.01% as low-zinc.
4) Alloys with more than 0.01% zinc are classified as uno-zinc, and those with less than 0.01% as zinc-containing.
Alloys with more than 0.01% zinc are classified as zinc-containing, and those with less than 0.01% as uno-zinc.
Porcelain binds to metal in PFM crown by:
1) Metallic bind
2) Mechanical bond
3) Chemical bond
4) Both 2 and 3
Dental Materials Answer: 4
Porcelain binds to metal in metal ceramic restorations by mechanical interlocking and chemical bonding. Mechanical interlocking is provided by proper wetting of the metal surface by porcelain.
The adherent metallic oxides, which are formed during the degassing cycle form a good chemical bond with porcelain.
Tin oxide and Indium oxide are formed from precious metal alloys while chromium oxide is formed from base metal alloys.
What is the water sorption value of poly (methyl methacrylate) according to the provided information?
1) 0.69 mg/cm²
2) 0.85 mg/cm²
3) 1.05 mg/cm²
4) There is no information provided on water sorption value
The text states that poly (methyl methacrylate) has a water sorption value of 0.69 mg/cm², which affects its dimensional stability and physical properties.
Gypsum Bonded Investment should NOT be heated above
1) 700°C
2) 750°C
3) 800°C
4) 900°C
Dental Materials Answer: 1
What is the significance of the line of force during the condensation of dental amalgam?
1) The line of force determines the speed at which the amalgam is condensed.
2) The line of force is the amount of force applied to the condenser during condensation.
3) The line of force describes the direction of force applied with a condenser.
4) The line of force is the amount of force needed to cause the amalgam to flow into the preparation.
The line of force refers to the direction in which the force is applied during condensation. It is crucial to apply the force in a controlled and precise manner to avoid causing damage to the tooth or the restoration. The text mentions that the force applied with a condenser parallels the long axis of the instrument shaft, with specific angles recommended for different areas of the cavity.