Restorative dentistry Flashcards
- What is the file used to explore the apical third of a canal called?
a. Searcher
b. Seeker
c. Finer
d. Endodontic explorer
e. Endodontic probe
B. Seeker
- The file used to explore the apical third of a tooth is usually:
a. Size 3-5
b. Size 8-10
c. Size 15-20
d. Size 25-30
e. Size 40-50
B. Size 8-10
- Which one of the following are you not looking for when you are exploring the apical third of a canal?
a. Hypercementosis
b. Branches
c. Lateral canals
d. Internal root resorption
e. Obstruction
A. Hypercementosis
Hypercementosis is found on the root surface of a tooth rather than inside the root canal. All the other can be found within the canal.
- The root canal you are working on is curved, and you have pre-curved the file accordingly. How can you best tell the direction the file is pointing within the root?
a. By mentally noting which direction the file is curved when inserting it
b. By looking at the position of the number on the side of the file
c. By cutting a notch on the rubber stop
d. By taking an intraoral periapical (IOPA) radiograph
e. By tactile sensation
D. By cutting a notch on the rubber stop
By cutting a notch in the rubber stop, you can tell which way the canal is curved. An IOPA is unnecessary for this purpose as it only gives you a two dimensional view of a three-dimensional object.
- If a canal is narrow, which one of the following can be used to make exploration easier?
a. Water
b. Bleach
c. EDTA
d. Calcium hydroxide
e. Ferric sulphate
C. EDTA
EDTA is a chelating agent which helps open partially sclerosed or narrow canals. Bleach would not help in exploration of the canal, but it would aid in the destruction of bacteria within the canals.
- In a straight-canal tooth, how much should the apical 1mm be prepared to?
a. The size of the first file which binds in that region.
b. Two to three sizes larger than the first file which binds within that region.
c. A size 30 file
d. A size 40 file
e. Depends on the tooth
B. Two to three sizes larger than the first file which binds within that region.
Ideally the apical 1mm should be prepared to two to three file sizes larger than the first file which binds in that area. This is because the infected dentine in that region needs to be removed enough to clean the area, but without compromising the apical seal.
- In the apical third of a tooth what percentage of canals are curved?
a. 5%
b. 30%
c. 60%
d. 90%
e. 100%
D. 90%
90% of teeth have some form of curve in the apical third.
- What technique is usually used for the production of an apical flare with hand files?
a. Crown down
b. Step down
c. Tug back
d. Step back
e. Step up
D. Step back
Step back is the most recognised method of producing an apical flare with hand instruments. Crown down is the accepted method of producing apical flare with rotary instruments. Tug back is the accepted method to find the apex of a tooth using tactile sensation.
- To create an apical flare, larger files are used at decreasing lengths. How much difference should there be between the lengths?
a. 0.5mm
b. 1mm
c. 1.5mm
d. 2mm
e. 3mm
B. 1mm
This is optimal to produce a good apical flare.
- What is the master apical file?
a. A file used to measure the length of the root.
b. A file used to clear debris from the apical region.
c. The first file which binds at the working length.
d. The file used to set the final diameter of the apical region preparation.
e. The file used to remove pulp material from the canal.
D. The file used to set the final diameter of the apical region preparation.
A barbed brooch is used to remove pulpal material from the canal. The file used to measure the length of the root is called working length file.
- What is patency filling?
a. A small file is pushed through the apex to keep it clear of debris.
b. A small file is used circumferentially on canal walls to prevent lateral canals betting blocked.
c. A nickel titanium rotary file is used to remove debris from the canal, keeping it clear.
d. A small file is used with bleach to clean the canal.
e. A small file is used to open the coronal part of the canal.
A. A small file is pushed through the apex to keep it clear of debris.
- Which of the following features is the most important in giving a canal resistance form?
a. Apical stop
b. Apical seat
c. Open apex
d. Natural anatomy
e. Tapering of canal walls
E. Tapering of canal walls
If you taper the canals, it gives them a good resistance form.
- A canal is prepared apically to a size 50 file. No files between size 30 and 50 can pass beyond the length. What type of apical preparation is this?
a. Apical stop
b. Apical seat
c. Open apex
d. Closed apex
e. Apical stricture
A. Apical stop
This describes the preparation of an apical stop.
- Which one of the following would you not use to make an apical flare?
a. K-flex
b. Ni-Ti rotary
c. GT (Greater Taper)
d. X-files
e. Hand files
D. X-files
All the others are genuine endodontic files – the x-files are not.
- Which one of the following is not relevant with regard to using rubber dam?
a. Latex allergy
b. Sleep apnoea
c. Claustrophobia
d. Sinusitis
e. Emphysema
B. As rubber dam is made of latex, A) is very important. Also, patients can feel claustrophobic when rubber dam is used. If a patient had sinusitis, they will have difficulty breathing through their nose, and having their mouths covered will be problematic. Patients with emphysema should not have anything impairing their airway, as they struggle for oxygen intake at the best of times.