ENDODONTICS/ Restorative PP

Question 1

Two PA radiographs showing lower anteriors 42,41,31 and 32. Which all treated endodontically with a post and core.

Parient is referred for per-radicular surgery , name two other treatment options?

Answer 1

• Extraction
• Re-rct

Question 2

Fractured MOD with exposed GP for 6 months , what would be your treatment and why?

Answer 2

• Re-rct , because the root canal system has been exposed for more than 3 months to the oral environment (bacteria)

Question 3

Name 3 features of the Nayyar core?

Answer 3

• Retention obtained from the undercuts in the divergent canals and pulp chamber
• 2-4mm GP removed from the canal and replaced with amalgam
• Coronal restoration can be done at the same appointment

Question 4

Name 2 restorative materials in dentistry that can bond amalgam to tooth?

Answer 4

RMGIC , GIC

Question 5

You are carrying out a root canal preparation of an upper right canine under local anesthesia , you are irrigating the canal with a dilute solution of sodium hypochlorite when the patient suddenly feels intense pain, within minutes you notice facial swelling in the area and bleeding into the root canal from peri-radicular tissues
* What is the most likely cause for these signs and symptoms and why?

Answer 5

Extrusion on sodium hypochlorite through the root canal apex which can be due to
* high pressure injection
* Injecting too deep (to wrong working length)
* locking the syringe into the canal

Question 6

preparation of an upper right canine under local anesthesia , you are irrigating the canal with a dilute solution of sodium hypochlorite when the patient suddenly feels intense pain, within minutes you notice facial swelling in the area and bleeding into the root canal from peri-radicular tissues

What would be your immediate action?

Answer 6

• Reassure patient that this is a complication that can happen and that it can be managed
• LA for pain relief
• Irrigate canal with copious amounts of saline
• Dress tooth with non setting calcium hydroxide

Question 7

preparation of an upper right canine under local anesthesia , you are irrigating the canal with a dilute solution of sodium hypochlorite when the patient suddenly feels intense pain, within minutes you notice facial swelling in the area and bleeding into the root canal from peri-radicular tissues

• What would be your management after immediate management?

Answer 7

• Priority must be given to pain relief and prevention of secondary infection
• Advise patient to use cold packs for the first days and then warm packs on the area of the swelling to prevent haematoma
• Prescribe analgesics (ibuprofen or paracetamol)
• Review patient within 24h

Question 8

preparation of an upper right canine under local anesthesia , you are irrigating the canal with a dilute solution of sodium hypochlorite when the patient suddenly feels intense pain, within minutes you notice facial swelling in the area and bleeding into the root canal from peri-radicular tissues

The prognosis of the tooth involved is not negatively affected by the NaoCL accident , you decide to continue with the established treatment after 4 weeks, how you would prevent what has happened

Answer 8

• Careful pre-operative radiographic assessment to ensure no open apices
• Provide bib and eyewear for the patient and use rubber dam
• Use chlorhexidine or saline first to irrigate the canal to test the integrity of rubber dam seal
• Ensure all syringes are labelled carefully
• Do not wedge the needle in the canal
• Set rubber stop of the needle 2mm short of the working length
• Depress syringe plunger with index finger rather than thumb
• Do not fill the syringe too much to make easier to handle

Question 9

What are the signs and symptoms of reversible pulpitis?

Answer 9

• Short sharp pain that last only few seconds after stimulus is removed
• TTP negative
• Pain on cold and sweet stimuli
• Localised pain that does not radiate

Question 10

How is reversible pulpitis managed?

Answer 10

• Removal of cause such as caries and restoration

Question 11

What are the signs and symptoms of irreversible pulpitis?

Answer 11

• Lingering pain after removal of stimuli
• TTP positive
• Dull aching pain that may radiate
• Spontaneous pain that keeps the patient awake at night
• Analgesics do not work
• Poorly localised

Question 12

How can irreversible pulpitis be managed?

Answer 12

• RCT
• XLA

Question 13

You are endodontically treating tooth 16 , you have prepared the canals , and now you are planning to obturate the root canal system , what 3 criteria must be fulfilled before obturation?

Answer 13

• Canal must be asymptomatic
• Root canals must be able to be dried
• Full biomechanical cleaning should have taken place

Question 14

Give 3 consistuents of GP other than GP ?

Answer 14

• Zinc oxide
• Radio-pacifiers
• Plasticisers
• Wax

Question 15

Give the functions of a sealer?

Answer 15

• Fill the space between the GP and the root canal walls
• Lubrication of the canal
• Provide a tight seal

Question 16

Give 3 common sealers used in the root canal system?

Answer 16

• Epoxy resin
• Calcium hydroxide
• Zinc oxide eugenol
• Glass ionomer cement

Question 17

How do you assess obturation on a radiograph?

Answer 17

• Check correct length
• Check there is no voids and well compacted
• Check all canals are filled

Question 18

What is the reason for obturation? (3)

Answer 18

• Seal remaining bacteria
• Provide apical and coronal seal
• Prevent reinfection

Question 19

Give 4 methods of obturation?

Answer 19

• Cold lateral compaction
• Warm vertical compaction
• Carrier based (GP)
• Warm lateral compaction
• Continuous wave compaction

Question 20

What percentage of maxillary first molars have an MB2 canal?

Answer 20

93%

Question 21

What are the 3 design objectives of endodontics?

Answer 21

• Continuously tapering funnel shape
• Maintain apical foramen in original position
• Keep apical opening as small as possible

Question 22

What are the advantages of the crown down technique?

Answer 22

• Removes bulk of infected tissue
• Creates a reservoir for irrigant
• Keeps reference point for working length which makes straight line access easier
• Limit spread of infected material at apical foramen

Question 23

Name 3 laws of pulpal floor anatomy?

Answer 23

• Law of colour - always darker
• Law of symmetry 1 - orifices lie equidistant from a line drawn in a mesio-distally through the pulp chamber except for maxillary molars
• Law of symmetry 2 - orifices lie perpendicular to a line drawn mesiodistally through the pulp chamber floor except for upper molars

Question 24

Give 3 rules for locating orifices in the pulpal floor?

Answer 24

• Always at junction of floor and wall
• Always at the angle of floor and wall junction
• Always at terminus of developmental fusion lines

Question 25

Give 4 reasons for irrigation during endodontic treatment?

Answer 25

• Mechanical preparation alone does not remove all bacteria
• Irrigation reaches areas that files cannot reach
• To flush out debris
• To dissolve organic and non organic content
• Remove the smear layer
• Lubrication

Question 26

Why is sodium hypochlorite a good irrigant?

Answer 26

• High antimicrobial activity
• Dissolve organic and non organic content ( collagen and necrotic tissue)

Question 27

What strength of NaOCl is used?

Answer 27

3%

Question 28

Name other common irrigant other than NaICl?

Answer 28

Chlorhexidine

Question 29

How is the smear layer removed?

Answer 29

• EDTA 17% which is chelating agent

Question 30

Name 2 intracanal medicaments?

Answer 30

• Corticosteroid and tetracyline paste (antimicrobial paste 5-7d ) - reduce pulpal inflammation
• Non setting calcium hydroxide - Antibacterial with low PH

Question 31

What are the landmarks for an inferior alveolar nerve block?

Answer 31

• Pterygomandibular raphe and coronoid notch and posterior border of the ramus - insert needle from contalateral premolar area in pterygomandibular space until contacting bone then retract

Question 32

Give 3 reasons for instrumentation of the root canal system?

Answer 32

• Remove infected tissue
• Allow irrigant access
• Make space for medicaments and obturation
• Create an environment for periradicular healing

Question 33

What advantages do protaper files have over K files?

Answer 33

• Shape memory
• Elasticity
• Decreased lateral pressure reducing the risk of ledges
• Decreased number of intruments needed
• increased cutting efficiency
• Easier to use

Question 34

Name 2 rotary endodontic systems?

Answer 34

• Reciproc
• Protaper

Question 35

Describe 2 other techniques other than reaming and filing?

Answer 35

• Watch winding - back and forth oscillation 30-60 degrees with light apical pressure
• Balanced force technique - Clockwise motion (1/4) then counterclockwise motion to (1/2) wit apical pressure

Question 36

Name 3 reasons why a file may separate ?

Answer 36

• Flexural stress due to repeated cyclic fatigue
• Torsional stress due to binding to canal walls
• Complicated curved canal anatomy

Question 37

Give 6 reasons why a patient with newly placed composite may be experiencing pain on biting ?

Answer 37

• High occlusion
• Polymerisation contraction stress
• Soggy bottom
• Cracked tooth syndrome
• Deep restoration close to the pulp without lining
• Debonded composite causing sensitivity

Question 38

5 restorative management techniques to minimise the problems in the previous question?

Answer 38

• Check occlusion with articulating paper
• Place composite in increments to one surface only to avoid polymerisations contraction stress
• Place composite in 2mm increments and ensure light curing to avoid soggy bottom
• Careful caries removal at pulpal floor with excavator or slow speed to avoid pulp irritation and ensure to place lining
• Cracket tooth syndrome - make sure good cuspal coverage
• Debonding of restoration - ensure good moisture control

Question 39

Give 3 reasons anterior guidance is preferred over posterior guidance?

Answer 39

• Easier to reproduce
• Protect teeth and restorations on posteriors
• Easy on muscles