MDS PREP
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.
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.
The final polish of a cat gold alloy to achieve a smooth polished surface is done by
1) Pickling
2) Electropolishing
3) Sandblasting
4) Rouge
Conservative Dentistry
Answer: 4
The final polish of a cast gold alloy to achieve a smooth polished surface is
done by
1) Pickling: This is a process used to remove oxides and impurities from the
surface of a metal before applying a final finish. However, it does not provide
the final polish.
2) Electropolishing: This technique uses an electrical current to dissolve the
metal surface and create a smooth finish, but it is not commonly used for gold
alloy restorations.
3) Sandblasting: This method involves propelling an abrasive material against
the metal surface to smooth and clean it, but it is too aggressive for the final
polish of a gold alloy restoration.
4) Rouge: Rouge is a fine abrasive paste used with a polishing wheel or point to
achieve the final polish on a cast gold alloy restoration. It removes minor
imperfections and gives a high luster to the metal.
The correct answer is 4) Rouge, as it is the standard technique for achieving a
smooth, polished surface on cast gold alloys.
Amount of force needed to condense direct filling gold depends on
1. Angle of compaction
2. Surface area of the condenser
3. Amount of the remaining dentin
4. Type of direct filling gold
Conservative Dentistry Answer: 2
Amount of force needed to condense direct filling gold depends on the surface
area of the condenser. The larger the surface area, the less pressure is
required to achieve proper condensation. The force applied affects the
compaction of the gold, but it is the size and shape of the condenser point that
dictate the actual pressure exerted on the material.
The CAD-CAM system uses
1) Cadmium in castings
2) A purcelain furnace with very high temperature
3) A video camera to all the prepared tooth
4) None of the above
Conservative Dentistry
Answer: 3
The CAD-CAM system utilizes digital imaging, often through a video camera or
scanner, to capture the prepared tooth for designing restorations.
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.
The base of class III preparation is
1) Axial wall
2) Gingival wall
3) Facial wall
4) Lingual wall
Conservative Dentistry
Answer: 1
In a Class III cavity preparation, which typically involves the anterior teeth and is located on the proximal surfaces, the axial wall is considered the base. This wall is oriented parallel to the long axis of the tooth and provides support for the restoration. The gingival wall is also important, but the axial wall is the primary base in this context.
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.