MDS PREP
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.
Pulp exposures of crowns come under which class according to WHO nomenclature
1. 873.60
2. 873.61
3. 873.62
4. 873.63
Endodontics
Answer: 3
Explanation: According to the WHO classification of dental injuries, pulp exposures due to crown fractures are classified under 873.62. This classification helps in standardizing the terminology used in dental trauma, allowing for better communication and understanding among dental professionals.873.60 - Pulp Exposure due to TraumaThis code refers to cases where the pulp is exposed as a result of trauma to the tooth. It does not specify whether the pulp is vital or non-vital, but it indicates that there is a direct exposure of the pulp tissue.873.61 - Avulsion of ToothThis code is used for cases where a tooth has been completely displaced from its socket (avulsed). In avulsion cases, the pulp is typically exposed, and immediate re-implantation is critical for the best prognosis. This classification highlights the severity of the injury and the need for urgent treatment.873.62 - Crown Fracture with Pulp InvolvementThis code refers to fractures of the crown of the tooth that involve the pulp. It indicates that the fracture has extended into the pulp chamber, necessitating treatment such as root canal therapy.873.63 - Crown Fracture without Pulp InvolvementThis code is used for crown fractures that do not involve the pulp. In these cases, the injury is limited to the enamel and dentin, and the pulp remains intact.
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.
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.
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.
Term "apical collar" (or) "apical seat" refers to
1. Resistance form of canal preparation
2. Located in apical 2 mm with parallel walls
3. Mechanically prepared portion of root canal
4. All of the above
Endodontics
Answer: 4
Which of the following fractures of tooth was poorest prognosis
1) Horizontal fractures at gingival level
2) Vertical root fractures
3) Horizontal fractures at apical third of root
4) Horizontal fractures at middle third or root
Endodontics
Answer: 2
Vertical root fractures are often associated with a poor prognosis because they can lead to significant loss of tooth structure and are difficult to treat. They typically result in the need for extraction, especially if they extend into the periodontal ligament or if the fracture is not detected early.