MDS PREP
Enamel fracture without tooth structure loss or incomplete enamel fracture results from
1. Concussion
2. Avulsion
3. Subluxation
4. None of the above
Endodontics
Answer: 1
Explanation: A concussion in dental trauma refers to a situation where the tooth
is not displaced but may have sustained an injury that can lead to an enamel
fracture. This type of injury does not involve loss of tooth structure, which
aligns with the description of an enamel fracture without tooth structure loss.
Formocresol produces tissue fixation and
1. Coagulative necrosis
2. Liquefactive necrosis
3. Cassious necrosis
4. Produces no necrosis
Endodontics
Answer: 1
Formocresol is a commonly used fixative and disinfectant in endodontic
treatment. It is known to produce tissue fixation by causing coagulative
necrosis. This is the process by which the proteins within the tissue are
coagulated or precipitated, leading to the death of cells due to dehydration and
denaturation. The necrotic tissue is then replaced by a fibrous connective
tissue, which is essential for the healing process in the periapical region
following root canal treatment.
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.
In class III Ellis fracture
1. Only enamel is involved
2. Enamel and dentin are involved
3. Enamel,dentin and pulp are involved
4. Non-vital pulp
Endodontics
Answer: 3
Class III: Enamel-Dentin-Pulp Fracture
Description: Involves enamel, dentin, and exposes
the pulp.
Endodontic Consideration: This type of fracture
typically requires endodontic treatment (root canal therapy) to manage
the exposed pulp and prevent infection. The prognosis depends on the
extent of the fracture and the vitality of the pulp.
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.
While combining NaOCH and H2O2 as irrigants
1) H2O2 should be used last
2) NaOCH should be used last
3) First irrigation should be done by normal saline
4) NaOCH and H2O2 should never be used simultaneously
Endodontics Answer: 2
Because residual H2O2 might react with debris and produce gas that can cause continuous pain.
Endodontically treated posterior teeth are more susceptible to fracture that untreated posterior teeth. The best explanation for this is
1. Moisture loss
2. Loss of root vitality
3. Plastic deformation of dentin
4. Destruction of the coronal architecture
Endodontics
Answer: 4
Loss of Coronal Structure: During endodontic treatment, the
coronal portion of the tooth may be significantly altered or reduced, especially
if there is extensive decay or if a crown is required after treatment. The loss
of tooth structure compromises the tooth's ability to withstand occlusal forces.
The irrigating should used with ultrasonic instruments used for preparation of root canal is
1) Sodium hypochlorite
2) Normal saline
3) Hydrogen peroxide
4) Chloramine
Endodontics
Answer: 1
Sodium hypochlorite is commonly used as an irrigating solution with ultrasonic instruments in endodontic treatment for its antimicrobial properties. It helps in the cleaning and disinfection of the root canal system by removing organic debris and bacteria. Normal saline, hydrogen peroxide, and chloramine are also used as irrigants, but sodium hypochlorite is the most effective in eliminating bacteria.