Restorative Dentistry

Question 1

A 32 year old woman presents with a fractured, vital, maxillary, second premolar with only the palatal cusp remaining. Which one of the following would be the most appropriate restoration?
a. Composite restoration
b. Porcelain-bonded crown
c. Porcelain inlay
d. Porcelain onlay
e. Porcelain jacket crown

Answer 1

D. Porcelain onlay
A porcelain onlay is the most appropriate treatment because it is the least destructive method and indirectly manufactured gives the best aesthetic and functional outcome.

Question 2

An 80 year old patient is complaining that her 20 year old complete dentures are very worn. On exam, you note that the polished surfaces are satisfactory and the FWS is 4mm. Which one of the following would be the most appropriate treatment option?
a. Copy/replica dentures
b. Implant retained maxillary and mandibular dentures
c. Implant retained mandibular denture and conventional maxillary denture
d. New conventional F/F dentures
e. Reline of existing dentures

Answer 2

A. Copy/replica dentures
It is unlikely to be possible to place implants in an 80 year old patient, due to the bone levels and normally his or her general health.

Question 3

A patient is referred to the oral surgery department with an apical area on a maxillary central incisor that has a post crown, but no root canal treatment. What is the appropriate course of treatment?
a. Oral antibiotics
b. XLA
c. Retrograde RCT with amalgam
d. Retrograde RCT with MTA (mineral trioxide aggregate)
e. Orthograde RCT

Answer 3

E. Orthograde RCT
Orthograde RCT of a non-root treated central incisor has the best rate of outcome for the tooth; however; it may not be the cheapest outcome.
Orthograde is the use of this material through the coronal access point vs. retrograde which is the use of the material from the apex of the tooth as in the example of apicoectomy.

Question 4

Which one of the following cannot be changed during the construction of a set of complete dentures?
a. Condylar guidance angle
b. Curve of Spee
c. Cuspal angle
d. Freeway space
e. Path of insertion

Answer 4

A. Condylar guidance angle
Condylar guidance angle is defined as ‘the angle at which the condyle moves away from a horizontal reference plane’. Therefore the condyle cannot be altered when making new dentures. All of the other options can be altered during denture construction.

Question 5

What is the file used to explore the apical third of a canal called?
a. Searcher
b. Seeker
c. Finder
d. Endodontic Explorer
e. Endodontic probe

Answer 5

B. Seeker

Question 6

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

Answer 6

B. Size 8-10
The file used to explore the apical third of a canal is called a seeker and is usually size 8-10.

Question 7

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

Answer 7

A. Hypercementosis
Hypercementosis is found on the root surface of a tooth rather than inside of the canal. All of the others can be found inside the canal.

Question 8

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 size of the file
c. By cutting a notch on the rubber stop
d. By taking a periapical
e. By tactile sensation

Answer 8

C. 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. A periapical is unnecessary for this purpose as it only gives you a 2D view or a 3D object.

Question 9

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

Answer 9

C. EDTA
EDTA is a chelating agent (removes toxic metals from the body) which helps open partially sclerosed or narrow canals. Bleach would not help in the exploration of the canal, but it would aid in the destruction of the bacteria within the canals.

Question 10

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

Answer 10

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 that 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.

Question 11

In the apical third of a tooth, what percentage of canals are curved?
a. 5%
b. 30%
c. 60%
d. 90%
e. 100%

Answer 11

D. 90%
90% of teeth have some form of curve in the apical third.

Question 12

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

Answer 12

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 an apical flare with rotary instruments. Tug back is the accepted method to find the apex of a tooth using tactile sensation.

Question 13

The create an apical flare, larger files are used at decreasing lengths. How much difference should there be between lengths?
a. 0.5mm
b. 1mm
c. 1.5mm
d. 2mm
e. 3mm

Answer 13

B. 1mm
This is optimal to produce a good apical flare.

Question 14

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

Answer 14

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 he length of the root is called the working length file.

Question 15

What is patency filing?
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 getting blocked
c. A nickel titanium rotary file is used to remove debris from the canal
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

Answer 15

A. A small file is pushed through the apex to keep it clear of debris

Question 16

Which of the following features is the most important in giving a canal resistance form?
a. Apical stop
b. Apical stent
c. Open apex
d. Natural anatomy
e. Tapering of canal walls

Answer 16

E. Tapering of canal walls
If you taper the canals, it gives them a good resistance form. Resistance form is the quality of a preparation shape that prevents rotational movement of the casting about a fixed point.

Question 17

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

Answer 17

A. Apical stop

Question 18

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

Answer 18

D. X-files
All the others are genuine endodontic files, the X-files are not.

Question 19

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

Answer 19

B. Sleep Apnoea
As rubber dam is made of latex, A is very important. Also, patients can feel claustrophobic when rubber dam is used. If a patient has 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 airways as they struggle for oxygen intake at the best of times.

Question 20

Which one of the following is not a function of a rubber dam, with regards to endodontics?
a. Decreases salivary contamination
b. Increases visibility
c. Contains excess irrigants
d. Makes pulpal access easier
e. Decreases medico-legal liability

Answer 20

D.
Although rubber dam increases visibility, it can sometimes make drilling the access cavity more difficult.

Question 21

If you cannot manage to place a rubber dam on a tooth, which one of the following solutions is unacceptable?
a. Parachute chain
b. Crown lengthening
c. No dam
d. Restore using a copper band
e. Placing the clamp beaks directly onto the gingivae

Answer 21

C. No dam
Parachute chain can be used to secure endodontic instruments to prevent aspiration. Crown lengthening and the use of a copper band can facilitate the placement of the clamp. It is not ideal to place beaks directly onto the gingivae, however, it is done in practice.

Question 22

Which one of the following is not a form of calcium hydroxide?
a. Life
b. Dycal
c. Hypocal
d. Coltosol
e. Apexit

Answer 22

D. Coltosol
Coltosol is a non-eugenol temporary restorative material. Apexit is an endodontic sealer. Dycal and Life are lining materials which can be used on minimal pulpal exposures. Hypocal is non-setting calcium hydroxide.

Question 23

Which one of the following statements about root caries is false?
a. It is more common in patients with reduced salivary flow than normal salivary flow
b. It is frequently managed with topical fluoride
c. It is frequently managed with systemic fluoride
d. It may be managed without a restoration
e. It occurs more in males than females

Answer 23

C.
Root caries is more common in men than women, in patients who are elderly and in those who have reduced salivary flow. It can be treated with topical fluoride and restorations or may be monitored if the caries is arrested.

Question 24

Which one of the following statements about tooth surface wear is correct?
a. Attrition is tooth surface wear by non-bacterial chemical dissolution
b. Abrasion is tooth wear by other teeth
c. Attrition is tooth wear by surfaces other than teeth
d. Erosion is tooth wear by non-bacterial chemical dissolution
e. Erosion is tooth wear by surfaces other than teeth

Answer 24

D. Erosion is tooth wear by non-bacterial chemical dissolution.
Attrition is tooth wear by other teeth. Abrasion is tooth wear by surfaces other than teeth.

Question 25

Which of the following statements about tooth surface loss is correct?
a. Abrasion is characterised by smooth wear facets
b. Erosion is characterised by smooth wear facets
c. Abrasion is the commonest type of wear in young patients
d. Abfraction is caused by stresses around the cervical margins due to flexure of teeth
e. Erosion by gastric acid is usually seen on the labial aspects of upper teeth

Answer 25

D. Abfraction is caused by stresses around the cervical margins due to flexure of teeth.
Attrition is characterised by smooth wear facets. The most common type of tooth wear in the young is erosion due to diet. Erosion by gastric acid is commonly seen on the palatal surfaces of upper anterior teeth, especially in bulimic patients.

Question 26

Which one of the following is not a method of monitoring tooth surface loss?
a. Dietary sheets
b. Study models
c. Smith and Knight indices
d. Laser scanning
e. Clinical photographs

Answer 26

A. Dietary sheets
Dietary sheets can be used to find the cause of the NCSTL but not monitor it.

Question 27

The desirable degree of taper of a preparation to receive a cast restoration is:
a. Less than 2 degrees
b. 2-4 degrees
c. 5-7 degrees
d. 8-12 degrees
e. Greater than 12 degrees

Answer 27

C. 5-7 degrees
The closer to parallel the walls of the preparation, the greater the resistance to placement. However, 5-7 degrees is acceptable.

Question 28

Which one of the following statements is true?
a. Enamel contains 92% hydroxyapatite by weight
b. Enamel is thinnest where it overlies the cusps
c. Diamond burs remove enamel by fracturing it
d. Tungsten carbide burs remove enamel by grinding
e. Stresses within a cavity preparation can be minimised by rounding the internal angle lines

Answer 28

E. Stresses within a cavity preparation can be minimised by rounding the internal angle lines.
Enamel is 97% hydroxyapatite by weight. Diamond burs grind away enamel and tungsten carbide burs fracture enamel. Enamel is thickest over the cusps.

Question 29

Which one of the following statements regarding surgical endodontics is true?
a. It is indicated for all failed root canal treatments
b. It is not indicated for patients who have pulp stones
c. It is indicated to prevent the removal of extensive coronal restorative work
d. It is indicated in the presence of a periapical radiolucency
e. It is contraindicated in multi-rooted teeth

Answer 29

C. It is indicated to prevent the removal of extensive coronal restorative work.
Apicectomy can be performed in teeth with extensive coronal restoration work and pulp stones, and can be performed in multirooted teeth. However, the percentage of success dramatically decreases in these teeth.

Question 30

Which one of the following problems occurs because of a reduced vertical dimension?
a. Difficulty with ‘S’ sounds
b. Poor appearance, showing far too much teeth
c. Clicking of the teeth when talking
d. Sunken lower face, elderly looking appearance
e. Poorly located pain in the lower denture bearing area that is relieved when the denture is removed

Answer 30

D. Sunken lower face, elderly looking appearance.
Patients with a reduced vertical dimension will have a sunken appearance.

Question 31

Which one of the following statements regarding overdentures is incorrect?
a. They are contraindicated in patients with cleft palates
b. They are contraindicated in patients with inadequate inter-arch space
c. They are contraindicated in patients with uncontrolled periodontal disease
d. They may be indicated when converting a partially dentate patient to a complete denture wearer
e. They may be indicated in patients with attrition

Answer 31

A.
The contraindications for overdentures are: poor OH, rampant caries and uncontrolled periodontal disease.

Question 32

Which one of the following statements regarding surveying of casts for denture design is correct?
a. It is carries out for complete and partial dentures
b. It is carried out for complete dentures
c. It can determine the occluso-vertical dimension
d. It can be used to determine undercuts with regard to the path of insertion of a denture
e. It is always carried out with the model at right angles to the the analyser rod

Answer 32

D. It can be used to determine undercuts with regard to the path of insertion of a denture.
Surveying is only carried out for partial dentures, and is used to determine a path of insertion and guide planes.

Question 33

Which one of the following statements regarding partial denture clasps is true?
a. In order to be functional, they must be resisted by a non-retentive clasp arm
b. Cast cobalt chrome clasps need to engage undercuts greater than 0.5mm
c. Stainless steel clasps are more flexible than gold clasps
d. The longer the clasp, the less flexible it will be
e. Gingivally approaching clasps are more conspicuous than occlusally approaching clasps

Answer 33

A. In order to be functional, they must be resisted by a non-retentive clasp arm.
Cast CoCr need to engage undercuts less than 0.25mm. Gold is more flexible than stainless steel, and the greater the length of a clasp, the greater the flexibility.

Question 34

Which one of the following is not an advantage of having an over-denture rather than complete dentures?
a. Better aesthetics
b. Preservation of alveolar bone
c. Better sensory feedback
d. Increased biting forces
e. More reproducible retruded jaw relations

Answer 34

A. Better aesthetics
Complete dentures and over dentures have the same aesthetic appeal. By retaining roots, the alveolar bone is retained and there is increased proprioception. By having greater retention from the abutments, the patient is able to produce increased biting forces compared with the complete denture wearer.

Question 35

The depth of reduction of the marginal ridge for an occlusal rest seat in a removable partial denture construction is:
a. 0.5mm
b. 1.5mm
c. 3mm
d. 5mm
e. None of the above

Answer 35

B. 1.5mm
The most optimal rest seat reduction is 1.5mm. If less reduction is performed, then the rest seat will struggle to retain. If there is greater reduction, then the tooth structure may be compromised.

Question 36

Cross-arch stabilisation is the main function of which one of the following parts of a removable partial denture?
a. Major connector
b. Minor connector
c. Bracing arm
d. Rest seat
e. Indirect retainer

Answer 36

A. Major connector
The major connector is the major part than connects the prosthetic teeth together.

Question 37

A denture which has bilateral free-ended partially edentulous saddles is classified as:
a. Kennedy Class I
b. Kennedy Class II
c. Kennedy Class III
d. Kennedy Class IV
e. Kennedy Class V

Answer 37

A. Kennedy Class I
Depending on where in the mouth the teeth are missing, edentulous situations can be grouped under four different categories.
Class I: Bilateral free-end
Class II: Unilateral free-end
Class III: Unilateral bounded
Class IV: Bilateral bounded anterior