prep week endo quiz

Question 1

What is primarily responsible for endodontic disease?

a. microleakage
b. cracks / fractures
c. microorganisms
d. dental caries
e. trauma

Answer 1

C - microorganisms

(bacterial is the predominant cause of endodontic disease but other organisms such as candida have also been identified in infected root canal systems)

Question 2

Which type of dentine is produced in response to an early carious lesion in the outer 1/3 of dentine?

a. tertiary
b. reparative
c. reactionary
d. primary
e. secondary

Answer 2

C - reactionary

(bacterial demineralisation of dentine stimulates reactionary dentine production from post-mitotic odontoblasts)

Question 3

True or False

Cold (refrigerant spray), EPT and drilling a test cavity are pulpal vitality tests.

Answer 3

False

These are sensibility tests which tests the ability of a tooth to respond to a stimulus.
(Vitality tests confirm blood flow within the pulp and include doppler flowmetry and pulse oximetry).

Question 4

Fibre-Optic Transillumination of a tooth is particularly useful in the diagnosis of what?

a. pulpitis
b. pulp necrosis
c. microleakage
d. cracked teeth
e. recurrent caries

Answer 4

D - cracked teeth

(light scatters upon reaching the crack line)

Question 5

Which theory most accurately describes the mechanism through which a pain can be elicited within teeth?

a. direct stimulation theory
b. excitation theory
c. ionic channel theory
d. hydrodynamic theory
e. thermodynamic theory

Answer 5

D - hydrodynamic theory

(proposes that squid movement in and out of the pulp chamber through dentinal tubules results in stimulation of nerve endings which can cause pain)

Question 6

The surface area of dentinal tubules at the ADJ is approximately 1% of the entire dentine surface area.

To what does this reportedly increase by in deep circumpulpal dentine?

a. 22%
b. 2%
c. 12%
d. 32%
e. 42%

Answer 6

A - 22%

Question 7

A patient presents with a buccal sinus tract adjacent to their upper right first permanent molar. The UR6 gives a -ve sensibility test result to cold and EPT, with a clear periapical radiolucency on radiographic examination.

What is the most likely diagnosis?

a. chronic apical abscess
b. perio-endo lesion
c. chronic apical periodontitis
d. acute apical abscess
e. acute apical periodontitis

Answer 7

A - chronic apical abscess

• characterised by longstanding infection which drains through a buccal fistula or sinus tract.
• radiographically: well defined PA radiolucency visible with -ve sensibility test due to pulpal necrosis.

Question 8

You are about to access a vital maxillary central incisor that has been diagnoses with irreversible pulpitis.

After gaining informed consent and delivering LA, what is the next stage of treatment?

a. gain written consent from the pt
b. create a triangular access cavity on the palatal surface
c. sensibility test the adjacent teeth to confirm diagnosis
d. dental dam isolation
e. perform a working length radiograph

Answer 8

D - dental dam isolation

Question 9

The Endo-Z bur is useful for which procedure?

a. gaining initial access to the pulp chamber
b. canal identification
c. de-roofing the pulp chamber
d. coronal flaring
e. gutta percha removal

Answer 9

C - de-roofing the pulp chamber

Question 10

Which of the following should not be used for working length determination due to it being unreliable?

a. radiographs
b. electronic apex locator
c. tactile sensation
d. paper points

Answer 10

C - tactile sensation

Question 11

The narrowest point of the canal is referred to as what?

a. apical constriction
b. root apex
c. apical delta
d. cemento-dentinal junction
e. major apical foramen

Answer 11

A - apical constriction

Question 12

You are performing working length determination on a maxillary lateral incisor using an electronic apex locator. You have inserted a size 10 K file into the canal and attached the file clip to the metal of the file.

Where do you attach the opposite end of the apex locator to complete the circuit?

a. maxillary lateral incisor undergoing endo tx
b. the lip
c. dental dam frame
d. index finger
e. the gingivae

Answer 12

B - the lip

(apex locator are designed with lip clips)

Question 13

Electronic Apex Locators can give working length determination accuracy in excess of what percentage?

a. 90%
b. 80%
c. 70%
d. 60%
e. 50%

Answer 13

A - 90%

Question 14

When performing working length determination on a mandibular molar, you can record in your clinical notes:

• the name of the canal you are measuring
• estimated working length from your pre-operative
• electronic apex locator ‘zero’ reading
• final working length

and which other important details?

Answer 14

The Coronal Reference Point

• essential landmark for safe and effective biomechanical preparation.
• without this, the canals will be inaccurately prepared.

Question 15

The access cavity shape for premolars is?

a. oval
b. trapezoidal
c. square
d. triangular
e. round

Answer 15

A - oval

Question 16

You are accessing a symptomatic mandibular premolar diagnosed with irreversible pulpitis and you wish to extirpate the entire pulp.

Which instrument is most appropriate to do this?

a. DG16
b. hedstrom file
c. barbed broach
d. muller pulp bur
e. k file

Answer 16

C - barbed broach

(specially adapted endodontic file designed to extirpate the pulp)

Question 17

Following endodontic access of a necrotic maxillary molar in a 20 year old pt, which file is most appropriate for scouting the canal and initiating the glide path?

a. ISO 15 hedstrom file
b. ISO 15 K file
c. ISO 10 hedstrom file
d. ISO 10 K file
e. wave one gold small, ISO 20 tip

Answer 17

D - ISO 10 K file

• if this failed to progress then a small K file could be used.

(K files are stainless steel files used to scout and negotiate canals and create an initial glide path.)

Question 18

Wave One Gold is an automated (engine-driven) file system.

What metal are Wave One Gold files fabricated from and what mechanism are they designed to be used with?

a. stainless steel, reciprocating file
b. stainless steel, rotary file
c. carbon steel, adaptive file
d. nickel-titanium, reciprocating file
e. nickel-titanium, rotary file

Answer 18

** D** - nickel-titanium, reciprocating file

Question 19

During biomechanical preparation, re-capitulation refers to the use of an ISO 10 K file taken to working length to confirm what?

a. master apical file
b. working length
c. apical gauging
d. patency
e. apical constriction

Answer 19

D - patency

(refers to keeping the apical constriction open or free from blockages with dentine mug)

Question 20

Which biomechanical preparation strategy is used to eliminate the majority of microorganisms in the coronal third of the canal before preparing the middle and apical thirds of the canal?

a. roane-balanced force
b. crown-down
c. step-back
d. double-flare
e. watch-winding

Answer 20

B - crown-down

(eliminates the bulk of microorganisms in the coronal 1/3 of the canal)

Question 21

What is the main irritant used in endodontics that dissolves organic material and has excellent antimicrobial activity?

a. chlorhexidine digluconate
b. hypochlorus acid
c. saline
d. sodium hypochlorite
e. ethylene diamine tetra acetic acid

Answer 21

D - sodium hypochlorite

Question 22

You are about to irrigate with sodium hypochlorite in maxillary canine with a working length of 26mm.

At what length should you bend your irrigating needle?

a. 26mm
b. 27mm
c. 25mm
d. 24mm
e. 28mm

Answer 22

D - 24mm

(bend 2mm short of the working length to ensure the needle tip remains short of the apical constriction throughout tx)