MDS PREP
Axial wall in class V cavity in transverse section appears
1. Convex mediodistally and uniformaly placed in the dentin
2. Straight with flat wall
3. Kidney shaped with converging mesial and distal
4. Concave shaped
Conservative Dentistry
Answer: 1
The axial wall in class V cavity in transverse section appears convex
mediodistally and uniformly placed in the dentin. This is because the cavity is
typically shallower in the center and deeper towards the line angles, providing
a good seal and preventing food and plaque accumulation.
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.
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.
When preparing adjacent class III cavities recommended procedures
1. Prepare large first but fill last
2. Prepare small first but fill last
3. Prepare and fill the small first
4. Prepare and fill the large first
Explanation: When dealing with adjacent Class III cavities, it is generally recommended to prepare the larger cavity first and fill it last. This approach allows the dentist to have better access and visibility when preparing the larger cavity, which can be more complex. Filling the larger cavity last helps to avoid contamination and ensures that the smaller cavity can be filled with precision without compromising the integrity of the larger 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 most common area for exposure is a Class V cavity in the first premolar. A Class V cavity is a five-sided cavity that involves the gingival margin of the tooth and the proximal surface. These cavities are particularly prone to exposure because the gingival tissue in this region can be thin, and the proximity to the bone can lead to inadvertent damage during the preparation process.
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.
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 product that is formed on the surface of the amalgam restoration and frequently results in discolouration is
1) Sulphide
2) Gamma I phase
3) Gamma II phase
4) Oxide
Conservative Dentistry
Answer: 1
The discoloration of amalgam restorations is often due to the formation of silver sulfide on the surface, which can occur due to the reaction of silver with sulfur compounds in the oral environment. The gamma I phase is a strong component of amalgam, while the gamma II phase is weaker and less stable. Oxides can form as well, but sulfides are more directly associated with the discoloration observed in clinical settings.