MDS PREP
Good supplement to radiographs in diagnosing class III caries clinically is
1) Caries activity tests
2) Examine colour changes below marginal ridges
3) Mirror and explorer
4) Vitality tests
Conservative Dentistry
Answer: 2
To diagnose class III caries clinically, which is caries that involves the proximal surfaces of teeth, a good supplement to radiographs is to examine the proximal surfaces for any color changes, particularly at the contact points where two teeth touch. This is often done using a combination of visual inspection and the use of a dental explorer to detect cavities and softened enamel. However, the answer provided, "Caries activity tests," refers to methods used to assess the activity or inactivity of a caries lesion, not necessarily for diagnosis.
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.
In modified class III cavity restoration, retention is obtained mainly by
1. Acid etching
2. Retentive groove/slot
3. Retentive point
4. Retentive pin
Conservative Dentistry
Answer: 1
Explanation: In modified Class III cavity restorations,
particularly those involving composite materials, retention is often achieved
through acid etching. This process creates micro-retentive features on the
enamel and dentin surfaces, allowing the bonding agent to penetrate and create a
strong bond with the tooth structure. While retentive grooves, points, and pins
can also be used, acid etching is a fundamental technique that enhances
retention in adhesive dentistry.
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.
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.
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.
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.
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
In Class V restorations, which are located at the gingival third of the facial or lingual surfaces of teeth, the occlusal wall is typically wider than the gingival wall. This design helps in providing retention and resistance to the restoration, as the occlusal wall is more subject to occlusal forces.