MDS PREP
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.
In modified class III cavity restoration, retention is obtained mainly by
1. Acid etching
2. Retentive groove/slot
3. Retentive point
4. Retentive pin
Conservative Dentistry
Answer: 1
Explanation: In modified Class III cavity restorations,
particularly those involving composite materials, retention is often achieved
through acid etching. This process creates micro-retentive features on the
enamel and dentin surfaces, allowing the bonding agent to penetrate and create a
strong bond with the tooth structure. While retentive grooves, points, and pins
can also be used, acid etching is a fundamental technique that enhances
retention in adhesive dentistry.
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.
In class III composite preparation, retention points should be placed
1. In the axial wall
2. Entirely in dentin
3. At the dentinoenamel junction
4. At the expense of facial and lingual wall
Conservative Dentistry
Answer: 2
Explanation: In Class III composite preparations, retention
points should be placed entirely in dentin. This is because dentin provides a
more reliable substrate for bonding compared to enamel, especially in areas
where the enamel may be thin or compromised. By placing retention points in
dentin, the restoration can achieve better mechanical retention and bonding
strength, which is crucial for 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.
The advantage of natural glaze compared to applied artificial glaze
1) More smooth finish is achieved
2) More permanent glaze is achieved
3) More shiny surface is achieved
4) All of the above
Conservative Dentistry
Answer: 2
Natural glaze is often more durable and permanent compared to applied artificial
glaze, providing a better finish.
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.
Outline form of a class V amalgam cavity preparation is related to (or) External shape of the class V amalgam restoration is related to
1. Contour of marginal gingiva
2. Axial line angles
3. Direction of the enamel rods
4. None of the above
Conservative Dentistry
Answer: 1
Explanation: The external shape of a Class V amalgam
restoration is closely related to the contour of the marginal gingiva. This is
important for aesthetic and functional reasons, as the restoration must blend
seamlessly with the surrounding gingival tissue. The outline form should respect
the natural contours to minimize plaque accumulation and promote periodontal
health. While axial line angles and the direction of enamel rods are relevant to
the preparation, they do not primarily dictate the external shape of the
restoration.