MDS PREP
Pit and fissure caries can be best pre vented by
1. the use of adhesive sealants
2. topical fluoride application
3. diet control
4. effective plaque control
Conservative Dentistry Answer: 1
1. The use of adhesive sealants: Adhesive sealants are thin, plastic coatings
applied to the chewing surfaces of the back teeth. They fill in the grooves and
depressions, creating a smooth surface that is easier to clean. Sealants act as
a barrier, preventing food and bacteria from lodging in these areas and thus
reducing the risk of tooth decay. This is considered the best preventive measure
because it directly addresses the anatomical vulnerability of the teeth and can
be applied quickly and painlessly.
2. Topical fluoride application: While topical fluoride is beneficial in
preventing dental cavities, it is not as effective as sealants in preventing pit
and fissure caries. Fluoride helps to strengthen the enamel and makes it more
resistant to acid attacks from plaque bacteria. However, because the pits and
fissures are already deep and narrow, fluoride may not always reach these areas
effectively. Sealants, on the other hand, provide a physical barrier that
fluoride cannot always penetrate.
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.
Which of the following restorative materials is likely to be eliminated in near future
1) Amalgams
2) Glass ionomer
3) Porcelain
4) Composites
Conservative Dentistry
Answer: 1
Dental amalgam has been a traditional restorative material for many years, known for its durability and strength. However, there is a growing trend towards the use of more aesthetic materials, such as composites and glass ionomers, which blend better with natural tooth structure.
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.
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.
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.
In conventional class III amalgam cavity preparation the axial wall in inciso gingival direction should be
1. Straight and parallel to the long axis of the crown, deeper incisally than gingivally
2. Convex and parallel to the long axis of the tooth
3. Concave and parallel to the incisogingival contour of the tooth
4. None of the above
Conservative Dentistry
Answer: 1
Explanation: In a conventional Class III amalgam cavity
preparation, the axial wall should be straight and parallel to the long axis of
the tooth. This design ensures that the restoration has adequate resistance form
and is less likely to dislodge under occlusal forces. The wall being deeper
incisally than gingivally helps to maintain the integrity of the tooth structure
and provides a stable base for the amalgam 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.