MDS PREP
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.
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.
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
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.
The principal cone of gutta-percha used for condensation should
1. Fit exactly at apex
2. Have a definite apical seal
3. Fit loosely in the canal
4. Be 2 mm from the apex
Endodontics
Answer: 2
In endodontics, the primary goal of using gutta-percha is to achieve a proper seal at the apex of the root canal system. A definite apical seal is crucial to prevent the ingress of bacteria and fluids, which can lead to reinfection. While the cone should fit well within the canal, the emphasis is on achieving a good seal rather than merely fitting exactly at the apex or being 2 mm from it.
The most common age group of fractures of permanent teeth
1. 8-12 years
2. 4-5 years
3. 1-2 years
4. 3-6 years
Endodontics
Answer: 1
Explanation: The age group of 8-12 years is commonly associated with the highest
incidence of dental fractures in permanent teeth. This is often due to increased
physical activity and sports participation during this developmental stage,
leading to a higher risk of trauma.
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.
Operator can identify root curvatures ledgings an additional curvatures by
1. Perception by instrumentation
2. Radiographic examination
3. By his knowledge of tooth anatomy
4. None of the above
Endodontics
Answer: 1
Identifying Root Curvatures
Perception by instrumentation refers to the tactile
feedback that a dentist can obtain while using instruments during
procedures, allowing them to identify curvatures in the root canal system.