MDS PREP
Smallest No. file is
1) 4
2) 6
3) 8
4) 10
Endodontics
Answer: 2
In endodontics, files are numbered according to their size, with smaller numbers indicating larger files. The smallest file commonly used is size 6.
The success of a root canal filling is best assessed
1. Clinical observation
2. Size of gutta-percha cone used
3. Radiographs
4. By the diameter of root canal reamer
Endodontics Answer: 1
The success of a root canal filling is primarily assessed through clinical
observation, which includes monitoring for signs of pain, swelling, and
infection. While radiographs and the size of the gutta-percha cone used can
provide additional information, the ultimate determinant of success is the
patient's symptom resolution and the absence of pathology.
Formocresol produces tissue fixation and
1. Coagulative necrosis
2. Liquefactive necrosis
3. Cassious necrosis
4. Produces no necrosis
Endodontics
Answer: 1
Formocresol is a commonly used fixative and disinfectant in endodontic
treatment. It is known to produce tissue fixation by causing coagulative
necrosis. This is the process by which the proteins within the tissue are
coagulated or precipitated, leading to the death of cells due to dehydration and
denaturation. The necrotic tissue is then replaced by a fibrous connective
tissue, which is essential for the healing process in the periapical region
following root canal treatment.
Perforation which has poorest prognosis is one that occur at
1) Furcation
2) Apical third
3) Coronal third
4) Middle third of root
Endodontics
Answer: 1
Perforations that occur in the furcation area of multi-rooted teeth have the poorest prognosis due to the complexity of the anatomy and the difficulty in achieving adequate sealing and healing. Furcation involvement often leads to periodontal issues and complicates treatment options, making it more challenging to maintain the tooth.
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.
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.
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.