Question: Cobalt-Chrominum alloys contains_______________?

• 1. 30% cobalt and 60% chrominum
• 2. 60% cobalt and 30% chrominum
• 3. 1% palladium
• 4. 20% gold

Question: The most commonly used Titanium alloy for dental and medical purposes is________________?

• 1. Ti 6Al 4V
• 2. Ti 5Al 4V
• 3. Ti 5Al 5V
• 4. Ti 6Al 6V

Question: Wax pattern is ideally invested immediately to decrease the dimensional changes caused by_______________?

• 1. Decrease flow
• 2. Continuous expansion
• 3. Relaxation of the internal stresses
• 4. Water loss

Question: The maximum carbon content of steel used in dentistry is__________________?

• 1. 19%
• 2. 2%
• 3. 1.7%
• 4. 4%

Question: Flux is used during casting to________________?

• 1. Remove the oxides formed on the gold alloy
• 2. Lower the melting point
• 3. Replace casting wax
• 4. Speed the burnout process

Question: Resistance to corrosion in a cobalt-chrome casting is due to presence of_______________?

• 1. High quality iron
• 2. Chrome
• 3. Cobalt
• 4. Nickel

Question: Which is the use of boxing an impression______________?

• 1. Ease of construction of denture
• 2. Preserving the sulci
• 3. Ease of pouring an impression
• 4. All of the above

Question: Gap between true end of casting ring and wax pattern should be______________?

• 1. ¼ inch
• 2. ½ inch
• 3. 3/8 inch
• 4. one inch

Question: Addition of large amounts of platinum to a casting gold alloy will________________?

• 1. Decrease its strength and ability to be hardened
• 2. Decrease its tarnish resistance
• 3. Increase its fusion temperature
• 4. Redden the alloy

Question: All of the following statements about cast cobalt alloy are true EXCEPT_____________?

• 1. They have a modulus of elasticity twice that of gold alloys
• 2. They are more rigid than gold alloys
• 3. They have higher ductility than gold alloys
• 4. They have a lower proportional limit than gold alloys