MDS PREP
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.
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.
During cavity preparation, more incidence of exposure is in
1. Class V cavity in first premolar
2. Class II mesioocclusal cavity
3. Class II distoocclusal cavity
4. Class IV cavity
Conservative Dentistry
Answer: 1
During cavity preparation, the incidence of pulpal exposure is higher in class V
cavities on first premolars due to the proximity of the margins to the pulp
horns.
Failure of casting to seat on the cast is overcome by
1) Scraping the cast to seat
2) Forcefully positioning the casting
3) Wash the casting with HCI
4) Discard if the discrepancy is more than 0.3 mm
Conservative Dentistry
Answer: 4
Failure of a cast to seat properly on the cast during the restoration process can be due to various factors such as distortion during fabrication or changes in the cast material. To overcome this, the cast can be scraped with a sharp instrument to remove any excess material that may be preventing proper seating. Washing the casting with HCI (hydrochloric acid) may help to clean and smooth the surface, but it is not a common practice for this specific purpose. Forcefully positioning the casting can cause damage to the cast and is not recommended. If the discrepancy is more than 0.3 mm, it is generally advised to discard the cast and make a new one to ensure a precise and accurate fit.
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.
Primary determinant of the outline form in class V preparation
1. Height of the gingival crest
2. Extension of the caries
3. Type of the restorative material
4. Teeth anatomy
Conservative Dentistry
Answer: 2
Explanation: The outline form of a Class V cavity preparation
is primarily determined by the extent of carious tissue. The goal is to remove
all carious dentin while preserving as much healthy tooth structure as possible.
The outline form must encompass the entire area affected by caries to ensure
that the restoration is effective and durable. Other factors, such as the height
of the gingival crest, type of restorative material, and tooth anatomy, may
influence the preparation but are secondary to the extent of caries.
The polishing agent which can be used to polish amalgam restoration is
1) Garnet
2) Emery
3) Silex
4) Alumina
Conservative Dentistry
Answer: 2
Emery is a polishing agent that can be used to polish amalgam restorations. It is a natural abrasive material that is relatively safe for metal surfaces and does not cause significant wear on the amalgam. Garnet, silex, and alumina are also abrasive materials, but they are less commonly used for polishing amalgam due to potential issues with scratching or wearing down the restoration.
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.