MDS PREP
Upper limit of urinary mercury attributed to extensive amalgam restoration
1) 1 microgram/g of creatinine
2) 3 microgram/g of creatinine
3) 2 microgram/g of creatinine
4) 4 microgram/g of creatinine
Conservative Dentistry
Answer: 4
The upper limit of urinary mercury attributed to extensive amalgam restoration is typically considered to be 4 micrograms/g of creatinine. While the actual limit can vary based on the individual and the extent of amalgam fillings, a level of 4 micrograms/g of creatinine is commonly used as a benchmark for evaluating potential health concerns related to mercury exposure from dental amalgam.
An old composite restoration is to be replaced. The best method is
1) To remove entire restoration, re-etch and refill
2) To roughen the old restoration, re-etch and refill
3) Composite restoration cannot be replaced or refilled
4) None of the above
Conservative Dentistry
Answer: 2
Roughening the old restoration and re-etching it allows for better bonding of the new composite material.
Lingual approach to the distal surface in canine for class III amalgam restoration is related to
1. Retention
2. Outline form
3. Resistance
4. Aesthetics
Explanation: The lingual approach to the distal surface of a canine for Class III amalgam restoration is primarily related to aesthetics. This approach minimizes visibility of the restoration from the facial aspect, which is important for maintaining the natural appearance of the tooth. Aesthetic considerations are particularly significant in anterior teeth, where the visibility of restorations can impact the overall smile and facial aesthetics. While retention, outline form, and resistance are important factors in cavity preparation, the lingual approach is specifically chosen to enhance the aesthetic outcome.
Which of the following restorative materials is likely to be eliminated in near future
1) Amalgams
2) Glass ionomer
3) Porcelain
4) Composites
Conservative Dentistry
Answer: 1
Dental amalgam has been a traditional restorative material for many years, known for its durability and strength. However, there is a growing trend towards the use of more aesthetic materials, such as composites and glass ionomers, which blend better with natural tooth structure.
Annealing of gold foil is the process by which
1. Contaminants are removed from the surface
2. Rigidity decreases and ductility increases
3. Both ductility and propotional limit decrease
4. None of the above
Conservative Dentistry
Answer: 1
Annealing gold foil is the process of heating gold to remove impurities and restore its cohesion properties. Annealing of gold foil is a heat treatment process used to alter the physical and sometimes chemical properties of the material. The primary purpose of annealing gold foil is to remove any contaminants and stresses that may be present on the surface of the material. This is achieved by heating the gold foil to a specific temperature, typically around 400°C (750°F), and then allowing it to cool slowly. The process can also help in improving the foil's ductility, making it more malleable and easier to work with. However, the direct effect of annealing on the rigidity, ductility, and proportional limit is not explicitly stated in the question, and thus the correct answer is that annealing of gold foil primarily serves to remove contaminants from the surface.
Aluminium oxide polishing powder is obtained from
1) Aluminium
2) Cryolite
3) Bauxite
4) Vulcanite
Conservative Dentistry
Answer: 3
Aluminium oxide (Al₂O₃) is primarily derived from bauxite, which is an ore that contains a high percentage of aluminium. The Bayer process is commonly used to extract aluminium oxide from bauxite.
By doubling the diameter of the condenser point and doubling the force applied, the operator is..............during condensation
1. Applying more pressure
2. Applying less pressure
3. Applying the same pressure
4. Pressure applied is variable
Conservative Dentistry
Answer: 2
By doubling the diameter of the condenser point and doubling the force applied,
the operator is actually applying less pressure during condensation. This is
because pressure is inversely proportional to the area of contact, which is
reduced by doubling the diameter of the condenser point. The increased force is
counteracted by the larger area of contact, resulting in a lower pressure per
unit area.
The best method to retract gingiva for class V composite restoration
1. Retraction ford
2. Electrosurgery
3. Rubber dam
4. All of the above
Conservative Dentistry
Answer: 3
For class V composite restoration, the best method to retract gingiva is by
using a rubber dam. This provides isolation, visualization, and moisture
control, which are crucial for successful adhesive techniques. While other
methods like retraction cords or electrosurgery may be used in some cases, they
are not the most suitable for routine class V restorations.