MDS PREP
Most frequent failures of root canal treated cases are due to
1. Inadequate obturation
2. Improper sterilization
3. Improper preparation
4. All of the above
Endodontics
Answer: 1
The most frequent failures of root canal treated cases are often due to
inadequate obturation. This can occur when the root canal filling material does
not completely fill the space or when it is not properly compacted, leaving gaps
where bacteria can persist and cause reinfection. Proper preparation and
sterilization are also crucial, but inadequate obturation is the most common
technical error leading to treatment failure.
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.
D2 on the endodontic file indicates
1) Diameter at tip of instrument
2) Angle of instrument
3) Length of instrument
4) 1/100th mm at end of cutting blade
Endodontics
Answer: 4
The designation "D2" on an endodontic file indicates the diameter of the file at
the tip, measured in hundredths of a millimeter. This helps clinicians select
the appropriate file size for root canal treatment.
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.
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.
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.
When pulp cannot be extirpated in narrow canals, which of the following can be used
1. Obtundant
2. Astringent
3. Haemostatic
4. Mummifying agent
Endodontics
Answer: 4
Explanation: A mummifying agent, such as paraformaldehyde,
is used to preserve the pulp in cases where extirpation is challenging. This
approach is often used as part of pulp therapy in certain endodontic treatments.
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.