MDS PREP
Finish lines of a complete coverage crown should be
1) Supragingivally
2) Subgingivally
3) Subgingivally if required
4) Gingival margin
Prosthodontics
Answer: 3
The finish line of a crown preparation can be placed supragingivally or subgingivally depending on the clinical situation. Subgingival finish lines may be necessary to achieve proper aesthetics, especially in cases where the margin needs to be hidden beneath the gingival tissue. However, it is important to avoid placing the finish line too far subgingivally, as this can complicate oral hygiene and lead to periodontal issues.
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.
Primary stress bearing area in maxillary complete denture is
1. Anterior palate
2. Buccal sulcus areas
3. Edentulous ridges
4. Posterior palatal area
Prosthodontics
Answer: 3
The primary stress-bearing area in maxillary complete denture is the edentulous ridges.
The effect of saliva on the denture prognosis
1. No effect
2. Affects denture retention
3. Tissue conditioners are indicated when there is reduction in salivary flow
4. None of the above
Prosthodontics
Answer: 2
The effect of saliva on denture prognosis affects denture retention.
The most reproducible relation of the jaws that is used in fixed denture construction
1) Centric occlusion
2) Centric relation
3) Protrusive contact position
4) Lateral contact position
Prosthodontics
Answer: 2
The most reproducible relation of the jaws that is used in fixed denture
construction is Centric Relation (CR). Here's a detailed explanation of the
options provided and why Centric Relation is the correct answer:
1) Centric Occlusion (CO): This is the position of the mandible where the
incisor and posterior teeth of the maxilla and mandible are in maximum
intercuspation, meaning the teeth are in their most closed and stable contact.
It is the position that occurs when the condyles are in the most superior and
anterior position in the glenoid fossae of the temporal bones. While important
for the function of the teeth, centric occlusion is not always a reliable
reference for the construction of a fixed denture, as it can be influenced by
various factors such as tooth wear, pathology, or parafunctional habits.
Moreover, it is a dynamic relationship that can change over time.
2) Centric Relation (CR): Centric relation is the most retruded, unstrained
position of the mandible on the maxilla from which the mandible can move to the
lateral and protrusive positions. It is the basis for the articulators in
dentistry and is considered the most reproducible jaw relationship for the
fabrication of fixed dentures. CR is determined by the temporomandibular joint
(TMJ) and does not involve tooth contact. This is crucial because it provides a
consistent and predictable starting point for constructing a denture that will
function harmoniously with the TMJ and the surrounding soft tissues. It is the
position where the condyles are in a centric relation with the fossa and the
disk is properly situated, which minimizes strain and maximizes stability during
function.
3) Protrusive Contact Position: This is the position of the mandible where the
incisor or canine teeth make contact with the maxilla in a forward and downward
movement. While it is a functional movement of the jaw, it is not a stable or
reproducible position for the construction of fixed dentures because it is
highly dependent on the muscles and may not be consistent across different
individuals or even during different occasions for the same individual.
4) Lateral Contact Position: This refers to the position of the mandible during
lateral movements, where the teeth contact the maxilla on the side of the arch.
Similar to protrusive contact, it is a functional position that is influenced by
muscle activity and not a stable reference for denture construction. Lateral
movements are also not the primary focus in fixed denture construction, which is
mainly concerned with the vertical and anteroposterior relationships of the
jaws.
In making a final impression for a complete denture, the most important area of the impression is
1. Ridge area of maxilla and buccal shelf of mandible
2. Lingual border area of mandible
3. Junction of hard and soft palate of maxilla and distolingual area of mandible
4. Mid palatel area of maxilla and ridge of the mandible
Prosthodontics
Answer: 3
In making a final impression for a complete denture, the most important area of the impression is the junction of hard and soft palate of maxilla and distolingual area of mandible.
One of the following rules explains about the grinding of certain cusps to produce balance in lateral movements
1) Ante"s rule
2) Bull rule
3) Wolf"s rule
4) Cieszynski"s rule
Prosthodontics
Answer: 2
The Bull rule pertains to the concept of occlusal balance during lateral
movements in dentistry. It suggests that certain cusps may need to be adjusted
or ground to achieve a balanced occlusion, particularly in the context of
removable prosthodontics or fixed restorations.
Ante's rule (option 1) relates to the relationship between the anterior and
posterior teeth in occlusion.
If a complete denture patient has genial tubercle at the level of the crest of mandibular ridge, the denture base
1. Can cover them
2. Should not cover them
3. Should cover them but relief is not necessary
4. Should cover them and relief is must
Prosthodontics
Answer: 4
If a complete denture patient has genial tubercle at the level of the crest of the mandibular ridge, the denture base should cover them and relief is a must.