MDS PREP
What is the typical film thickness required for zinc polycarboxylate cement?
1) 50 µm
2) 25 µm
3) 15 µm
4) 5 µm
As a luting material, zinc polycarboxylate should form a film of less than 25 µm.
What are the stoichiometric formulas for the gamma (?), epsilon (?), and zeta (?) phases in dental amalgams?
1) ?: Ag3Sn, ?: Cu3Sn8, ?: Cu3Sn
2) ?: Ag3Sn, ?: AgSn, ?: CuSn
3) ?: AgSn, ?: Cu3Sn, ?: Ag3Sn8
4) ?: AgSn, ?: CuSn, ?: Ag3Sn.
?: Ag3Sn, ?: Cu3Sn8, ?: Cu3Sn
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.
What is the primary component of zinc polycarboxylate cement?
1) Zinc oxide
2) Polyacrylic acid
3) Titanium dioxide
4) Calcium hydroxide
Zinc polycarboxylate cement primarily consists of zinc oxide and polyacrylic acid.
What is the typical film thickness required for a luting material?
1) 50 µm
2) 25 µm
3) 15 µm
4) 5 µm
For effective luting, the material should form a thin film, typically around 25 µm.
Which type of amalgam alloy has the lowest compressive strength at 1 hour?
1) High-copper lathe-cut alloy
2) Low-copper lathe-cut alloy
3) High-copper spherical alloy
4) Low-copper spherical alloy
The compressive strength at 1 hour is lowest for the low-copper lathe-cut alloy, which is 45 MPa.
Which of the following denture base materials has the highest linear shrinkage?
1) High-impact acrylic resin
2) Vinyl acrylic resin
3) Conventional acrylic resin
4) Rapid heat-cured acrylic resin
Rapid heat-cured acrylic resin has the highest linear shrinkage at 0.97%, which can affect the fit and stability of the denture.
What type of dental cement is used in cases of rampant caries and unhygienic oral conditions?
1) Zinc polyacrylate
2) Calcium sulfate
3) Zinc oxide-eugenol
4) Calcium hydroxide
Calcium hydroxide is used in cases of rampant caries and unhygienic oral conditions due to its antibacterial and tissue-dissolving properties.