Endo failure Flashcards
assessment of RCT outcome
- Root canal treatment should be assessed at least after 1 year and subsequently as required
- Absence of pain, swelling and other symptoms
- No sinus tract
- No loss of function
- Radiological evidence of a normal PDL
uncertain outcome
if radiographic changes remain the same size or has only diminished in size. In this situation it is advised to assess the lesion further until it has resolved or for a minimum period of 4 years. If a lesion persists after 4 years the root canal treatment is usually considered to be associated with post-treatment disease.
RCT has unfavourable outcome when (4)
- The tooth is associated with signs and symptoms of infection
- A radiologically visible lesion has appeared subsequent to treatment or a pre-existing lesion has increased in size
- A lesion has remained the same size or has only diminished in size during the 4-year assessment period
- Signs of continuing root resorption are present
In these situations it is advised that the tooth requires further treatment.
exceptions to RCT failure
extensive radiological lesion may heal but leave a locally visible, irregularly mineralized area. This defect may be scar tissue formation rather than a sign of persisting apical periodontitis. The tooth should continue to be assessed
ESE guidelines for endo success
strict radiographic criteria
technical Vs Biological outcome of success
it’s not just about the white line radiolucency around the apex
why do RCTs fail
“Most failures occur when treatment procedures, mostly of a technical nature, have not reached a satisfactory standard for the control and elimination of infection”
4 factors that are significant in RCT failure
pre-op factors affecting success
- presence or absence of a lesion
- operative factors contributing to success
- filling extruding to within 2mm of radiographic apex but not extruded
- well condensed root filling with no voids
- good quality coronal restoration
3 technical complications leading to biological failure
- Coronal leakage
- Difficult to establish causality
- Currently - good coronal restoration coupled with good quality root canal treatment
additional factors that can contribute to failure (7)
- Presence of a sinus
- Increased lesion size
- No perforation
- Getting patency
- Penultimate rinse with EDTA (reRCT)
- Avoiding mixing CHX and NaOCl
- Absence of a flare up
what can cause failure in biological objective
missed canals
- no MB2, probably just not found it yet
improve hit rate by
know anatomy of pulp chamber and floor
centrality and concentricity
law of symmetry I
Except for maxillary molars, the orifices of the canals are equidistant from a line drawn in a mesial-distal direction through the pulp-chamber floor
law of centrality
the floor of the pulp chamber is always located in the centre of the tooth at the level of the CEJ
law of concentricity
the walls of the pulp chamber are always concentric to the external surface of the tooth at the level of the CEJ
low of the CEJ
the CEJ is the most consistent, repeatable land mark for locating the position of the pulp chamber
law of symmetry II
except for the maxillary molars, the orifices of the canals lie on a line perpendicular to a line drawn in a mesial-distal direction across the centre of the floor of the pulp chamber
law of colour change
the colour of the pulp-chamber floor is always darker than the wall
law of orifice location I
the orifices of the root canals are always located at the junction of the walls and the floor
law of orifice location II
the orifices of the root canals are located at the angles in the floor-wall junction
law of orifice location III
the orifices of the root canals are located at the terminus of the root developmental fusion lines
2 factors which contribute to success
- Achieve and maintain patency
- Blockages can be due to severe curvature
2 types iatrogenic damage contributing to RCT failure
avoid creation of ledges
avoid separation of instrument
6 factors to avoid creation of ledges
- Poor planning
- Poor access
- Poor length control
- Forcing instruments
- Failure to observe sequence
- Failure to maintain patency
