MDS PREP
Gingivally the depth of a class V cavity is
1. 0.5-1 mm
2. 0.75-1 mm
3. 1-1.25 mm
4. 2-3 mm
Conservative Dentistry
Answer: 2
Gingivally, the depth of a class V cavity is typically 0.75-1 mm. This depth is
sufficient to provide a good bond with the tooth structure and prevent
microleakage without causing significant gingival irritation or damage.
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.
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.
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.
The main disadvantages of composites of not being recommended for class II posterior restorations
1. Colour matching is not good
2. Lacks sufficient strength
3. Occlusal wear
4. Frequent fractures at the isthmus
Conservative Dentistry
Answer: 3
One of the main disadvantages of composite materials in Class II posterior restorations is their susceptibility to occlusal wear, which can compromise the longevity of the restoration.
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.
Upper limit of urinary mercury attributed to extensive amalgam restoration
1) 1 microgram/g of creatinine
2) 3 microgram/g of creatinine
3) 2 microgram/g of creatinine
4) 4 microgram/g of creatinine
Conservative Dentistry
Answer: 4
The upper limit of urinary mercury attributed to extensive amalgam restoration is typically considered to be 4 micrograms/g of creatinine. While the actual limit can vary based on the individual and the extent of amalgam fillings, a level of 4 micrograms/g of creatinine is commonly used as a benchmark for evaluating potential health concerns related to mercury exposure from dental amalgam.
A proximal carious lesion in a radiograph is
1) Usually larger than clinically
2) Smaller than clinically
3) Same as clinically
4) An incipient lesion
Conservative Dentistry
Answer: 2
Proximal carious lesions often appear smaller on radiographs than they are
clinically due to the limitations of radiographic imaging.