Endodontic Complications Flashcards
When do complications occur?
- access cavity
- mechanical prep
- obturation
What can happen during access cavity?
missed canals
perforations
Why do missed canals occur?
inaccurate pre-op radiograph assessment
lack of knowledge
incomplete deroofing
How to avoid missing canals?
Accurate pre-operative radiograph assessment
Know the anatomy
Complete deroofing
Dentine Map
Why do perforations occur?
Searching for the canals with high-speed bur
Inaccurate assessment of pulp chamber location
Not following the long axis of the tooth
Color difference
How to avoid perforations?
Pre-operative radiograph assessment Kranser and Rankow laws
Assess tooth angulation
NEVER look for the canal with a highspeed
What are the kranser and rankows laws?
Law of symmetry 1: the mesiobuccal (MB) and distobuccal (DB) root canal orifices are equidistant to the lingual (L) orifice on a line draw in a mesial-distal direction across the center of the floor of the pulp chamber (M-D line)
Law of symmetry 2: the orifices of the canals lie on a line perpendicular to M-D line
Law of Color Change: the color of the pulp-chamber floor is always darker than the walls,
Law of Orifice Location 1 and 2: the orifices of the root canals are located at the angles in the floor-wall junction
Law of Orifice Location 3: the orifices of the root canals are located at the terminus of the root developmental fusion lines
Where are orifices located?
located at the level of CEJ
What can happen during mechanical preparation?
blockage
zipping
strip/root perforations
ledge
What causes a ledge?
- Incomplete deroofing
- Incorrect determination of working length
- Forcing GG into the canal
- Skipping files
- Not having straight line access
- Using large SS files around a curve
- Negotiating calcified canals
- Not frequently irrigating
- Not checking patency
How to avoid ledges?
- Complete deroofing
- Establish an accurate working length
- Never skip files
- Always irrigate
- Always check patency
- Always pre-curve files (especially stainless steel)
- Use NiTi files in curved canals
- Get straight line access
- Avoid using post drills if possible
What are the causes of separated instruments?
- Unwinding
- Instrument bending or crimping
- Excessive bending
- Not establishing glide path
- Not having straight line access
- Forcing instruments into the canal
- Insufficient irrigation
- Not checking patency
- Using large instruments in narrow canals
- Using large files around curvatures
Why do instruments seperate?
torsional stress
cyclic fatigue
How to solve a broken file?
try to retrieve with ultrasonic
bypassing (leaving it)
How does apical zipping occur?
- Introducing large size files to the working length
- Keeping the rotary file rotating around the curve close to or at the apical constriction
