MDS PREP
Gutta-percha cones should not be used for root canal filling in
1. Primary teeth
2. Permanent mandibular last molars
3. Teeth with wide root canal
4. Teeth with curved roots
Endodontics
Answer: 1
Gutta-percha cones are generally not recommended for root canal filling in
primary teeth because the root canals of primary teeth are more likely to
contain vital tissue, and the material can potentially cause harm to these
tissues. However, they are suitable for permanent teeth with wide root canals
and even those with curved roots, provided that the root canals are properly
cleaned and shaped to allow for optimal filling.
The disadvantage of glass bead sterilizer
1) Only small instruments can be sterilized
2) Variable temperature
3) Does not produce effective heat for sterilization
4) All of the above
Endodontics
Answer: 1
Explanation:
One of the main disadvantages of glass bead sterilizers is that they are limited to sterilizing only small instruments due to the size of the sterilization chamber. Larger instruments cannot be effectively sterilized in this type of device.
Moderate extrusion of obturating material and sealer beyond the apex is undesirable because
1. The prognosis is poor
2. There is likelihood of postoperative discomfort
3. Sealer is usually not resorbed and gutta-percha may cause severe perirdicular reaction in periapical tissue
4. All of the above
Endodontics
Answer: 4
When moderate extrusion of obturating material and sealer beyond the apex
occurs, it is undesirable for several reasons. While it does not necessarily
mean the prognosis is poor, there is a higher likelihood of postoperative
discomfort due to the potential for chemical irritation of the periapical
tissues. Additionally, if the sealer is not resorbed, it may cause a foreign
body reaction, and gutta-percha extrusion can sometimes lead to severe
periradicular reactions. The best approach in such a case is to obturate the
remaining canal up to the point of obstruction and observe the patient's
symptoms and healing response.
Enlargement of the calcified canals is done with
1. EDTA
2. Calcium hydroxide
3. Sodium hypochlorite
4. Sodium chloride
Endodontics
Answer: 1
EDTA (ethylenediaminetetraacetic acid) is a chelating agent commonly used in endodontics to remove the smear layer and facilitate the enlargement of calcified canals. It helps in dissolving inorganic components of the dentin, making it easier to access and clean the root canal system.
The filling of choice for primary root canals
1. ZOE
2. Calcium hydroxide
3. Gutta-percha
4. Chlorpercha
Endodontics
Answer: 1
Zinc oxide eugenol is commonly used as a filling material for primary root canals due to its biocompatibility and sealing properties.
Perforation which has poorest prognosis is one that occur at
1. Furcation
2. Apical third
3. Coronal third
4. Middle third of root
Endodontics
Answer: 1
Explanation: Furcation perforations occur in the area where the roots of a multi-rooted tooth diverge. These perforations are particularly challenging to manage because they can lead to periodontal disease and loss of attachment in the furcation area. The prognosis is poor due to the difficulty in achieving adequate sealing and maintaining periodontal health in this area, making it more susceptible to infection and further complications.
Sonic and ultrasonic instruments have in common
1) Used for flaring coronal portion of root-canal
2) Use copious amounts of irrigating solutions
3) Easy to control while operating
4) All of the above
Endodontics
Answer: 2
Both sonic and ultrasonic instruments are used in dental procedures, particularly in endodontics and scaling. They generate vibrations that help in the removal of debris and biofilm. A key feature of these instruments is that they require the use of copious amounts of irrigating solutions to enhance their effectiveness, cool the instrument, and flush out debris. While they may also be used for flaring coronal portions of root canals and can be controlled during operation, the commonality that stands out is the need for irrigating solutions.
Endodontic therapy is said to be successful when following changes occur in periapical region
1. Formation of cementum
2. Regeneration of alveolar bone
3. Regeneration of PD ligament
4. All of the above
Endodontics
Answer: 4
When it comes to assessing the success of endodontic therapy, the changes that
occur in the periapical region are crucial indicators. A successful treatment
typically results in the formation of new cementum, regeneration of the alveolar
bone, and regeneration of the periodontal ligament. These processes are all part
of the body's natural healing response to the removal of infection and the
introduction of a biocompatible filling material in the root canal system. Thus,
all of the above factors contribute to the overall success of the treatment.