MDS PREP
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.
The disadvantage of glass bead sterilizer
1) Only small instruments can be sterilized
2) Variable temperature
3) Does not produce effective heat for sterilization
4) All of the above
Endodontics
Answer: 1
Explanation:
One of the main disadvantages of glass bead sterilizers is that they are limited to sterilizing only small instruments due to the size of the sterilization chamber. Larger instruments cannot be effectively sterilized in this type of device.
In hot bead sterilizer, temperature is highest in
1. Inner zone of the sterilizer
2. Outer zone of the sterilizer
3. Equal in both outer and inner zone
4. Variable
Endodontics
Answer: 2
In a hot bead sterilizer, the temperature is highest in the inner zone of the sterilizer. A hot bead sterilizer uses a heated metal bead to transfer heat to the instruments, which are placed around the bead in a basket. The inner zone is where the bead is located and where the temperature can reach up to 300°C, which is sufficient to kill microorganisms and sterilize the instruments. The outer zone is cooler and does not contribute significantly to the sterilization process.
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.
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 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.
According to WHO nomenclature of pulp injuries, "avulsion" is classified of pulp injuries as
1. 873.60
2. 873.61
3. 873.68
4. 873.69
Endodontics
Answer: 2
Explanation: In the WHO classification, avulsion refers to the complete
displacement of a tooth from its socket, and it is classified under 873.61. This
classification is crucial for understanding the severity of the injury and
determining the appropriate treatment.
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.