MDS PREP
There is a real relationship between the incidence of fractured anterior teeth and the
1. Caries in those teeth
2. Hardness of the enamel
3. Hardness of the dentin
4. Protrusion of those teeth
Endodontics
Answer: 4
Explanation: Protruded anterior teeth are more susceptible to trauma and
fractures due to their position and exposure. This anatomical relationship
highlights the importance of considering tooth positioning in dental trauma
cases.
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.
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.
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.
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 length of the instrument used for endodontic implants is
1) 25 mm
2) 28 mm
3) 21 mm
4) 40 mm
Endodontics
Answer: 4
Endodontic instruments, particularly those used for root canal treatment and
implants, typically have a length of around 40 mm. This length allows for
adequate reach into the root canals of most teeth, which can vary in depth.
Instruments shorter than this may not effectively reach the apical areas of the
root canals.
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.
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.