MDS PREP
What is the typical setting time for a Class I dental stone?
1) Less than 10 minutes.
2) 10-30 minutes.
3) 30-60 minutes.
4) More than 60 minutes.
Class I (dental stone) has a longer setting time than impression plaster but is stronger and more dimensionally stable, making it suitable for fabricating models.
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 purpose of using temporary cementing materials in dentistry?
1) To permanently fix the prosthesis
2) To allow for temporary fixation of a prosthesis for patient approval
3) To provide a long-term seal against microleakage
4) To strengthen the tooth structure
Temporary cementing materials are used for trial of the temporary appliance for a few days to get patient approval and to ensure it has suitable consistency and can be easily dislodged during permanent cementation.
What is the maximum allowable level of mercury in the blood according to the given information?
1) 1 µg/L
2) 3 µg/L
3) 5 µg/L
4) 10 µg/L
The maximum allowable level of mercury in the blood is specifically mentioned as 3 µg/L in the provided text.
What is the modified form of zinc oxide-eugenol used for temporary cementation?
1) Type I
2) Type II
3) Type III
4) Type IV
The modified form of zinc oxide-eugenol used for temporary cementation is commonly known as Type II due to its lower compressive strength and ease of removal.
What is the effect of over- or under-triturating amalgam on its compressive and tensile strength?
1) Over-triturating increases both compressive and tensile strength in all amalgams.
2) Under-triturating increases both compressive and tensile strength in all amalgams.
3) Over-triturating decreases both compressive and tensile strength in all amalgams.
4) Over-triturating increases creep and under-triturating decreases it.
Over-triturating increases creep, and under-triturating lowers it.
What is the primary mechanism of bonding for resin-modified glass ionomer cements?
1) Micromechanical retention
2) Chemical bonding to tooth structure
3) Ionic bonding
4) Physical adsorption
Resin-modified glass ionomer cements bond through micromechanical retention and chemical bonding.
What is the typical setting time for zinc oxide-eugenol temporary cement?
1) Less than 5 minutes
2) 5-10 minutes
3) 10-15 minutes
4) More than 15 minutes
Zinc oxide-eugenol temporary cement typically sets in about 5-10 minutes.