MDS PREP
In periapical lesions of average size, time needed for osteogenesis is
1. 1-2 months
2. 2-6 months
3. 6-12 months
4. 2 weeks
Endodontics
Answer: 3
Osteogenesis in periapical lesions of average size generally requires a
significant amount of time, typically falling within the range of 6-12 months.
This period allows for the complete healing of bone tissue around the root apex.
Activity of disinfectants is
1) Reduced by organic debris or blood
2) Increased with heat
3) Hastened by adding 5 % oxygen
4) Nullified by ethylene dioxide gas
Endodontics
Answer: 1
Activity of disinfectants is indeed reduced by organic debris or blood. This is because organic materials can act as a barrier, protecting microorganisms from the disinfectant and reducing its effectiveness. The presence of organic matter can bind to the disinfectant, inactivate it, or consume it, thereby reducing its ability to kill or inhibit the growth of microorganisms. For this reason, it is essential to thoroughly clean and debride the area before applying a disinfectant to ensure optimal efficacy.
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.
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.
Which condensation of gutta-percha, tip of the instrument is broken at apical third of canal. You would like to
1. Dissolve gutta-percha and retrieve the broken piece
2. Obturate remaining canal up to the point of obstruction, and observation
3. Do periapical surgery and apicectomy to remove broken piece
4. All of the above
Endodontics
Answer: 2
Finally, if the tip of the gutta-percha condensation instrument breaks in the
apical third of the root canal, the most common practice is to simply continue
with the obturation up to the point of obstruction. Attempting to dissolve the
gutta-percha or performing surgery to retrieve the broken piece may not be
necessary and can potentially cause further damage. Instead, the area is sealed,
and the body's natural healing processes are allowed to occur.
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.
In Ellis classification of injured teeth a class IV represents
1. Non-vital tooth
2. Avulsed tooth
3. Fracture involving only the enamel
4. Fracture involving enamel and dentin but not pulp
Endodontics
Answer: 1
Explanation: Class IV in the Ellis classification indicates a fracture that has
resulted in pulp exposure, often leading to a non-vital tooth.
Class IV: Crown Fracture with Pulp Involvement
Description: Extensive fracture involving enamel, dentin, and pulp, often with significant loss of tooth structure.Endodontic Consideration: Endodontic treatment is necessary due to pulp exposure. The tooth may require additional restorative procedures after root canal therapy to restore function and aesthetics.
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.