MDS PREP
Apart from composites and ceramics, another material that could be copy milled easily and inexpensively is:
1) Molybdenum
2) Germanium
3) Titanium
4) Chromium
Dental Materials Answer: 3
Fabrication of ceramics and metals like titanium that are difficult to cast, is done by CAD-CAM process and copy milling.
What is the role of MDPB in dental composites?
1) It provides improved mechanical properties.
2) It acts as an initiator for the polymerization reaction.
3) It enhances the antibacterial activity of the composite material.
4) It reduces the viscosity of the resin.
MDPB (methacryloxy decyl pyridinium bromide) is a quaternary ammonium salt that has been shown to be effective against various streptococci in dental composites. Its inclusion enhances the antibacterial properties of the material.
What is the purpose of using a temporary cement?
1) To provide a permanent seal
2) To allow for temporary fixation before the final restoration is placed
3) To strengthen the tooth structure
4) To fill gaps caused by caries
Temporary cements are used to hold a temporary restoration in place until the final restoration can be placed, and they should have a lower compressive strength to allow for easy removal.
Which of the following shows highest permanent deformation following strain in compression :
1) Polysulphide impression material
2) Polyether impression material
3) Condensation silicones
4) Addition silicones
Dental Materials Answer: 1
For permanent deformation following strain in compression, ranking is mentioned below:
Polysulfide > polyethers > condensation silicone > addition silicone
What is the effect of acid etching on dentin bond strength?
1) It decreases bond strength.
2) It has no effect on bond strength.
3) It increases bond strength.
4) It is unpredictable.
Acid etching of dentin creates a micro porous surface that allows for better infiltration and mechanical interlocking of the bonding agent, leading to improved bond strength between the restorative material and the tooth structure.
What is the typical range of pH for acidic dental cements?
1) pH > 7
2) pH 7-10
3) pH 4-7
4) pH < 4
Acidic dental cements typically have a pH less than 7.
What is the typical average particle size of powered gold used in dental restorations?
1) 15 ?ms
2) 10 ?ms
3) 5 ?ms
4) 20 ?ms
The average particle size of powered gold used in dental restorations is 15 ?ms. This size allows for the gold to be manipulated and condensed properly within the cavity preparation to achieve the desired restorative outcome.
What is the typical composition of Zinc Oxide-Eugenol Cement?
1) Zinc oxide and polyacrylic acid
2) Zinc oxide and eugenol
3) Zinc phosphate and polyacrylic acid
4) Zinc oxide and sodium silicate
Zinc Oxide-Eugenol Cement is primarily composed of zinc oxide and eugenol, with a pH of approximately 7, making it less irritating to pulpal tissues.