MDS PREP
Retention grooves are placed in a class V cavity for non-adhesive restoration in
1. Mesioaxial and distoaxial line angles
2. Occlusoaxial and gingivoaxial line angles
3. All line angles of the cavity
4. None of the above
Conservative Dentistry
Answer: 2
Retention grooves in a class V cavity for non-adhesive restoration are placed in
the mesioaxial and distoaxial line angles. These grooves help hold the
restoration in place by providing mechanical retention and reducing the risk of
microleakage.
The mesial and distal cavity margins for class V gold restoration
1. Should end at the line angles of the tooth
2. Should be converging
3. Should extend into the proximal surfaces
4. All of the above
Conservative Dentistry
Answer: 1
For a class V gold restoration, the mesial and distal cavity margins should end
at the line angles of the tooth to ensure proper adaptation and prevent
overhangs. This is important for both functional and aesthetic reasons
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.
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.
Which of the following is the functionally generated occlusal registration in an indirect gold casting technique
1) Centric relation
2) Anatomic registration
3) Restration of the envelope of occlusion
4) Static registration of dynamic occlusion
Conservative Dentistry
Answer: 4
In indirect gold casting techniques, occlusal registration is crucial for ensuring that the final restoration fits properly in the patient's occlusion. "Static registration of dynamic occlusion" refers to capturing the occlusal relationship when the patient is in a static position, which is essential for creating a functional restoration.
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.
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.
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.