Urgent managemnt of procedural incidents

Question 1

What procedural errors can occur in endodontics?

Answer 1

File separation, perforation, extrusion of sodium hypochlorite, other errors (e.g., voids in obturation, extrusion of obturation material, transportation of canal).

Question 2

What are the 2 modes files can fracture?

Answer 2

Cyclic fatigue and torsional fatigue.

Question 3

What is cyclic fatigue?

Answer 3

When an instrument is rotated in a curved canal due to repeated compressive and tensile stresses.

Question 4

What is torsional fatigue?

Answer 4

Occurs when the tip of the file binds in the canal and the motor continues to rotate.

Question 5

Which instruments do not show plastic deformation (Warning sign for file fracture)?

Answer 5

NiTi files.

Question 6

Which type of file is more likely to fracture?

Answer 6

NiTi.

Question 7

Where do files most commonly fracture?

Answer 7

Apical third.

Question 8

What can be done to minimise risk of file fracture?

Answer 8

Ensure straight line access, avoid overuse of files, ensure speed and torque settings are correct, inspect files for unwinding during use, continually move files within canal in no more than 3 strokes, continual irrigation and flushing of debris, advance files gradually by maximum of 2mm at a time.

Question 9

What can be done to manage file fracture in coronal third of a vital tooth?

Answer 9

Remove file aiming for minimum dentine removal.

Question 10

What can be done to manage file fracture in the mid third of a vital tooth?

Answer 10

Attempt to bypass the file, if not try to obturate fragment, monitor, if failure, consider surgical options.

Question 11

How to manage file fracture in apical third of a vital tooth?

Answer 11

Obturate canal up to fragment.

Question 12

How to manage file fracture in non-vital teeth?

Answer 12

Bypass if possible, do not need to remove. If bypass unsuccessful, inter-appt medicament (CaOH)2 for 2-4 weeks combined with NaOCl agitation follow up.

Question 13

What are the two main types of perforation?

Answer 13

Iatrogenic accident and pathologic.

Question 14

Give 3 reasons for pathologic perforation.

Answer 14

Resorptive, carious, fracture.

Question 15

Where can perforations in coronal third occur?

Answer 15

Lateral and furcal.

Question 16

When do perforations in coronal third often occur?

Answer 16

When trying to locate canal orifices.

Question 17

What are the 2 types of perforation in the mid third?

Answer 17

Strip and lateral.

Question 18

When do strip perforations occur?

Answer 18

Cured canal is instrumented too heavily on the inside surface.

Question 19

Where can perforations in the apical third occur?

Answer 19

Apical and lateral.

Question 20

How prevalent are iatrogenic perforations?

Answer 20

3-10% of all endodontically treated teeth.

Question 21

In which arch are perforations more likely?

Answer 21

Maxilla.

Question 22

What signs might indicate a perforation?

Answer 22

Bleeding, pain (if no LA given), consistent apex locator readings of 0 above apex.

Question 23

What late signs may indicate a perforation?

Answer 23

Radiography, ST pathology (inflammation/sinus), CBCT.

Question 24

What factors affect the prognosis of perforation?

Answer 24

Site (supracrestal or apical), size, time to repair.

Question 25

How can the risk of perforation be reduced?

Answer 25

Use magnification and good lighting, remove impediments to straight line access, use pre-op imaging and take intra-op images as needed, ensure glide path with size 20 hand file before using rotary, copious, gentle irrigation, balancing force technique for hand files, follow manufacturer protocols, never force a file, do not use rotary if suspect a blockage/ledge, in multirooted teeth, always brush the file away from the furcation.

Question 26

How to manage perforations?

Answer 26

Magnification, assessment of prognosis, repair with hydraulic calcium silicate cement if possible, if not possible, consider surgical approach, monitor, consider referral.

Question 27

What is recapitulation?

Answer 27

Between each new rotary file, use a smaller hand file. This prevents blockages.

Question 28

What damage can be caused by NaOCl extrusion?

Answer 28

Pain, oedema, ulceration, bruising, cellulitis, trismus, allergic response, damage to adjacent structures.

Question 29

With which teeth is trismus most likely to occur?

Answer 29

Lower molars.

Question 30

Which sex is more commonly affected by NaOCl extrusion?

Answer 30

Female.

Question 31

What intra-operative factors can affect the severity of NaOCl extrusion?

Answer 31

Size of apical opening, force applied when irrigating, concentration of NaOCl, volume extruded, position of irrigant tip, irrigant tip gauge and shape.

Question 32

What can be done to reduce the risk of NaOCl extrusion?

Answer 32

Use of rubber dam, measure files to correct working length, use of stoppers for irrigation syringes, use of safe ended needles, use of index finger instead of thumb for irrigation, ensure syringe is not locked in canal by using an in and out motion during irrigation, passive movement of syringe, ask patient to signal if they get a bad taste, use of a lower concentration of NaOCl.

Question 33

Which type of syringes should be used for irrigation?

Answer 33

Side venting.

Question 34

What distance from apical constriction can you effectively irrigate?

Answer 34

4mm.

Question 35

How to immediately manage a NaOCl accident?

Answer 35

Block LA to manage pain, insert paper point to remove excess NaOCl, irrigate canal with saline (water if saline not available), let canal drain, aided with further paper points, dress tooth with calcium hydroxide and temporary filling, pain management - more LA / OTC analgesics, swelling management - NSAIDs.

Question 36

What ongoing management should occur for NaOCl extrusion?

Answer 36

Telephone follow up on same day/evening, daily phone calls for next few days, RV in 1 week, if necrosis, prescribe antibiotics - amoxicillin or metronidazole, can consider other medications (e.g., steroids/antihistamines), refer to maxfax if concerned with sequelae, call patient 1-2 times a week until satisfied it is resolved, only obturate once symptoms have resolved.

Question 37

What is the duty of candour?

Answer 37

Ethical responsibility of all healthcare workers to be open and honest, even when something goes wrong.