MDS PREP
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.
The main disadvantages of composites of not being recommended for class II posterior restorations
1. Colour matching is not good
2. Lacks sufficient strength
3. Occlusal wear
4. Frequent fractures at the isthmus
Conservative Dentistry
Answer: 3
One of the main disadvantages of composite materials in Class II posterior restorations is their susceptibility to occlusal wear, which can compromise the longevity of the restoration.
When dental bur is sterlized by autoclaving, which of the following chemicals is used for protection of the bur
1) Sodium nitrate
2) Sodium nitrite
3) Silver nitrate
4) Silver nitrite
Conservative Dentistry
Answer: 2
Explanation:Sodium nitrite is often used as a protective agent during the autoclaving process to prevent corrosion of dental instruments, including burs. It helps to maintain the integrity of the metal during the sterilization process.
Pit and fissure caries can be best pre vented by
1. the use of adhesive sealants
2. topical fluoride application
3. diet control
4. effective plaque control
Conservative Dentistry Answer: 1
1. The use of adhesive sealants: Adhesive sealants are thin, plastic coatings
applied to the chewing surfaces of the back teeth. They fill in the grooves and
depressions, creating a smooth surface that is easier to clean. Sealants act as
a barrier, preventing food and bacteria from lodging in these areas and thus
reducing the risk of tooth decay. This is considered the best preventive measure
because it directly addresses the anatomical vulnerability of the teeth and can
be applied quickly and painlessly.
2. Topical fluoride application: While topical fluoride is beneficial in
preventing dental cavities, it is not as effective as sealants in preventing pit
and fissure caries. Fluoride helps to strengthen the enamel and makes it more
resistant to acid attacks from plaque bacteria. However, because the pits and
fissures are already deep and narrow, fluoride may not always reach these areas
effectively. Sealants, on the other hand, provide a physical barrier that
fluoride cannot always penetrate.
Main feature of class V amalgam restoration
1. Occlusal wall is greater than gingival wall
2. Retention undercuts placed in the mesial and distal walls
3. Axial wall is flat and does not follow the contours of the tooth
4. Mesial and distal walls converge
Conservative Dentistry
Answer: 1
Explanation: In a Class V amalgam restoration, the occlusal
wall (or the wall facing the occlusal surface) is typically wider than the
gingival wall (the wall facing the gingiva). This design feature helps to
provide adequate bulk for the restoration, ensuring strength and resistance to
fracture. The other options, such as retention undercuts and wall convergence,
are not characteristic features of Class V restorations, which are primarily
concerned with the gingival and occlusal relationships.
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.
In class V preparation the wall which is not present at all
1. Pulpal
2. Distal
3. Mesial
4. Axial
Conservative Dentistry
Answer: 1
In class V preparation, the pulpal wall is not present at all, as the cavity is
confined to the cervical third of the tooth. It does not extend into the pulp
chamber.
How much fraction of methyl mercuryis absorbed from gut
1)20%
2)50%
3)80%
4)100%
Conservative Dentistry
Answer: 4
100% of methyl mercury is absorbed from the gut. After absorption methyl mercury binds to hemoglobin, circulates systemically and is distributed to all organs, including the brain