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.
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.
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.
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.
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
The protrusion of anterior teeth can increase the risk of fractures due to their position and exposure to occlusal forces. Protruded teeth are more susceptible to trauma and stress during biting and chewing, which can lead to fractures. Additionally, protruded teeth may not have adequate support from adjacent teeth, further increasing their vulnerability to fracture.
Which of the following statements is false?
1) The upper first premolar usually has two canals
2) Root canal instruments are best sterilized by a chemical method
3) All root canals must be enlarged to at least a size 25 file
4) All are false
Endodontics
Answer: 2
1) The upper first premolar usually has two canals: This statement is true. While the presence of two canals in the upper first premolar is not guaranteed, it is quite common to find two canals in this tooth.
2) Root canal instruments are best sterilized by a chemical method: This statement is false. The best method for sterilizing root canal instruments is heat sterilization using an autoclave. Chemical methods can be used for surface disinfection but are not adequate for sterilization.
3) All root canals must be enlarged to at least a size 25 file: This statement is true. Enlarging the root canals to a size 25 or larger is a part of the cleaning and shaping process in root canal therapy to ensure thorough debridement and preparation for filling.
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.
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.