MDS PREP
When loads are placed on the abutment tooth, all of the following result except
1) Widening if the periodontal ligament
2) Increase in the density of the cortical plates
3) Increase in the trabeculation of the alveolar bone
4) None of the above
Prosthodontics
Answer: 4
Effects of loading on the abutment tooth and the surrounding structures.
Widening of the periodontal ligament: When loads are
applied to a tooth, the periodontal ligament (PDL) experiences stress. This
can lead to a mild widening of the PDL space due to the mechanical loading
and adaptive responses of the tissues involved. Thus, this statement is
true.
Increase in the density of the cortical plates: When
there is functional loading, the cortical bone surrounding the teeth can
adapt by increasing in density (a process known as bone remodeling).
Increased loads can stimulate bone formation, leading to denser cortical
plates. This statement is also true.
Increase in the trabeculation of the alveolar bone:
Similar to the cortical plates, the trabecular (or cancellous) bone also
adapts to loads through a process of remodeling, often leading to increased
trabeculation during functional loading. This means denser and more
organized bone structure in response to the applied forces, which is true as
well.
None of the above: Given that all the previous
statements can be considered true in the context of what happens when loads
are applied to the abutment tooth, the option "None of the above" suggests
that all of the listed outcomes can occur with loading on the abutment
tooth, making option 4 the correct choice.
In summary, when loads are placed on the abutment tooth, all the mentioned
effects (widening of the periodontal ligament, increase in the density of the
cortical plates, and increase in the trabeculation of the alveolar bone) are
valid responses to mechanical stress. Therefore, the answer 4 (None of the
above) is correct because there are no false statements among the listed
outcomes.
When recording jaw relations, the danger of displacing the baseplates can be
minimized by
1. fabricating wax occlusal rims
2. lining the baseplate with acrylic resin
3. fabricating compound occlusal rims
4. lining the baseplate with zinc oxide-eugenol impression paste
Prosthodontics
Answer: 4
Explanation: Lining the baseplate with zinc oxide-eugenol impression paste
provides a more stable and accurate fit during jaw relation records. This
material can help capture the contours of the underlying tissues and minimize
movement of the baseplate, thus reducing the risk of displacing it during the
recording process. The other options may not provide the same level of
stability.
When acrylic resin is packed in the sandy stage, it may result in
1) Open bite
2) Porosity
3) Increased strength
4) All of the above
Prosthodontics
Answer: 2
Packing acrylic resin in the sandy stage, which refers to a stage where the material is not fully polymerized and has a grainy texture, can lead to porosity in the final product. This occurs because the incomplete packing can trap air bubbles, resulting in a porous structure that compromises the strength and integrity of the restoration.
A patient with a -4mm overbite can be classified to have which type of malocclusion?
Prosthodontics Answer: 3
1. Deep bite
2. Crossbite
3. Openbite
4. Class II
A patient with a -4mm overbite can be classified to have an open bite.
Only pure hinge movements of the mandible occur at
1. Centric occlusion
2. Centric relation
3. Lateral occlusion
4. Terminal hinge position
Prosthodontics
Answer: 4
Only pure hinge movements of the mandible occur at terminal hinge position.
To allow space for the dentures, most tuberosity reduction require
1. Only soft fibrous tissue removal
2. Large part of the bone to be removed
3. Removal of bone always
4. Reduction of bone always on both sides
Prosthodontics
Answer: 1
To allow space for the dentures, most tuberosity reduction requires only soft fibrous tissue removal.
After extraction and healing, the maxillary denture encloses severe bony undercuts in both the tuberosities. The best treatment for this condition
1. Reduce the undercuts on one side to allow the path of insertion
2. Reduce both the undercuts so that no bony undercuts exists anywhere on the ridge
3. Use selective pressure technique to displace the tuberosity
4. Do the surgical trimming of the ridge and allow the undercuts to exist
Prosthodontics
Answer: 2
After extraction and healing, the maxillary denture encloses severe bony undercuts in both the tuberosities. The best treatment for this condition is to reduce both the undercuts so that no bony undercuts exist anywhere on the ridge.
A dental instrument which creates aerosols containing large number of microorganisms is the
1. Evacuator
2. Ultrasonic scaler
3. Amalgam condenser
4. Endodontic reamer
Prosthodontics
Answer: 2
A dental instrument which creates aerosols containing a large number of microorganisms is the ultrasonic scaler.