Endodontic Errors

1. S U B J E C T: O P E R AT I V E D E N T I S T RY
B Y: D R . M U H A M M A D A L I A R S H A D
ENDODONTIC ERRORS

2. DEFINITION
• Any mistake that occurs at some point during root
canal treatment.

3. TREATMENT OF THE WRONG TOOTH
• Etiology:
Either misdiagnosis or inattention.
Prevention:
a) Ensure correct diagnosis through detailed history
and examination.
b) Mark the tooth which requires treatment (with a
pen/marker!).
• Management:
a)Complete the treatment of both teeth
b)Inform the patient

4. MISSED CANALS
• Most common canals to be missed:
Mesio-palatal (MB2) of maxillary molars
Canals in the distal roots of mandibular molars
Second canals in lower incisors
Second canals in lower premolars
Third canals in upper pre-molars.
• Prevention:
Prepare adequate access cavity
Always expect there will be an extra canal.
Use magnification (surgical microscope or loupes)
Check angled radiographs
CBCT (Cone-Beam Computed Tomography)

7. CROWN FRACTURE
• Access cavities weaken the crown.
• Crown fractures can occur during preparation or
between appointments.
• One of the frequent causes is failure to relieve the
occlusion.
• Restorability needs to be checked before proceeding
with the treatment.

8. PERFORATIONS
Definition:
• Pathologic or iatrogenic communication between the pulp space and the
oral or peri-radicular tissues.
Etiology:
A- Iatrogenic:
• Misaligned use of burs during access preparation and search for canal
orifices
• During efforts to negotiate calcified and curved canals
• Overzealous instrumentation towards a root concavity (Strip perforation)
• Inappropriate post space preparation
B- Pathological:
• Caries
• Root resorption

9. • Bacterial infection emanating either from the root canal
or the periodontal tissues, or both, prevents healing and
brings about inflammatory sequels.
• This results in pain, suppurations, abscesses, and
fistulae.
• Once an infectious process has established itself at the
perforation site, prognosis for treatment is precarious
and extraction may be needed.
Prognosis of perforations:
• Whether or not a root perforation can be successfully
treated depends on whether the perforation can be
repaired such that bacterial infection of the perforation
site can either be prevented or eliminated.
• Prognosis depends on:
Time
Size
Location
Adequacy of seal

11. Detection and determination of perforation:
• Sudden bleeding and pain during instrumentation.
• The patient may complain of NaOCl taste.
• Angled radiographs taken with a radiopaque instrument
in the suspected perforation.
• Electronic apex locators can accurately determine the
location of root perforations.
• A narrow isolated deep periodontal pocket is a possible
sign of periodontal breakthrough due to root perforation.
Management:
• Regain access to the root canal space to complete
disinfection
• Hemorrhage control
• Provision of adequate seal
• Materials used include:
GIC
MTA/ Biodentine

13. INSTRUMENTATION-RELATED
ERRORS

14. LEDGE
• When the tip of an inflexible instrument with a
cutting tip gouges into the wall of a curved canal.
• Causes loss of the working length
• Smaller flexible instruments with non-cutting tips are
pre-curved in order to regain access to the original
canal.

15. ZIP AND TRANSPORTATION
• Zipping is the result of the tendency of an instrument
to straighten inside a curved root canal.
• This results in over-enlargement of the outer side of
the curvature and under-preparation of the inner
aspect at the apical end point.
• Therefore, the terms straightening, deviation,
transportation and hour-glass shape are also used to
describe this type of defect.

16. APICAL PERFORATIONS
• May occur as a result of preparation with inflexible
instruments with a sharp cutting tip.

17. STRIP PERFORATION
• Due to overzealous instrumentation towards the
inner wall of a curved canal.
• Common in mesial roots of lower molars and ribbon-
shaped premolars.

18. APICAL BLOCKAGE
• Apical blockage of the root canal occurs as a result
of packing of tissue or debris and results in loss of
patency and working length.
• As a consequence complete disinfection of the most
apical part of the root canal system is not possible
• Patency filing & thorough irrigation are important to
prevent blockage.

19. INSTRUMENT SEPARATION
• The two most common causes of instrument separation
are instrument fatigue from overuse, and applying
excessive apical pressure, usually with a rotary motion.
• Management options:
Retrieval
Bypass
Instrumentation and obturation to the # file level
Surgical options: (apicectomy, root amputation/ hemi-
section, intentional replantation)
Extraction

20. SODIUM HYPOCHLORITE ACCIDENT
• NaOCl is extremely caustic and tissue toxic.
• Forcibly injecting NaOCl into the peri-apical tissues
can have disastrous consequences.
• The patient immediately complains of severe pain
and swelling. This is followed by ecchymosis,
paresthesia, tissue necrosis, scarring, and muscle
weakness.
• Concentration is important! (0.5% vs. 6%)
• Early realization is key.
• It is not a chlorine allergy! But rather a dentist-
induced error!

22. Prevention:
• Passive placement of the irrigating needle (no wedging).
• Side-vented or notched needles are recommended.
• No great force is exerted on the plunger of the syringe
(use index finger)
• Use lower concentrations of sodium hypochlorite.
• Strict working length control
Management:
• Copious irrigation with saline or sterile water.
• Strong analgesics
• Antibiotics (if needed)
• Ice packs
• Antihistamines and intra-muscular steroids
• Hospitalization and surgical intervention may be needed.

23. SUBCUTANEOUS TISSUE EMPHYSEMA
• Collection of air (or another gas) below the subcutaneous
tissues.
• Relatively uncommon.
Two actions may cause this to happen:
A blast of air to dry a canal (more likely to happen with
youngsters, in whom the canals in anterior teeth are relatively
large)
Exhaust air from a high-speed drill directed toward the tissue.
The usual sequence of events is rapid swelling, erythema, and
crepitus.
• It is usually a benign condition that resolves over 3–10 days as
the gas is resorbed into the blood stream for eventual excretion
via the lungs.
• Complications (although rare) include: pneumomediastinum,
airway compromise and death!

25. Prevention:
• Use paper points. Do not blow air directly down an
open canal.
• Employ a hand piece that exhausts the spent air out
the back of the hand piece rather than into the
operating field.
Management:
• Reassurance
• Referral and hospitalization
• A course of antibiotics designed to cover normal
oral flora (weak evidence)

26. INSTRUMENT ASPIRATION AND
INGESTION
• Aspiration and ingestion of foreign objects are
potential complications that can occur during dental
procedure, such as root canal therapy, implantation,
extraction, and even routine examination. The
foreign object included endodontic instruments,
implant components, burs, posts, teeth, orthodontic
brackets, restorations and even dental mirror and
irrigation needle.

28. Prevention & Management:
• Always use a rubber dam!
• If one insists on placing rubber dam clamps before
the dam is placed, the clamp should be fitted with a
long string of dental floss to aid in its recovery
• If instrument aspiration or ingestion is apparent, the
patient must be taken immediately to a medical
emergency facility for examination, and the dentist
must accompany the patient.
• Radiography of the thorax and abdomen. (It is
helpful if the dentist takes a sample file along so the
radiologist has a better idea of what to look for)
• Surgical intervention would be the only solution.