Endodontic Failure Flashcards
how to assess outcome
absence of pain, swelling etc
no sinus tract, no loss of function
radiographic evidence of normal PDL
how often should outcome of RCT be assesed
at least 1 year after and subsequently as required
unfavourable RC outcomes
- tooth associated with signs/symptoms of infection
- radiograph visible lesion appeared after tx or preexisiting lesion increased in size
- exisiting lesion remained same size or only diminished in size during 4yr assessmet
- signs of continuing root resoprtion
exceptions to unfavourable outcomes
extensive radiological lesion may heal but leave a locally visible, irregularly mineralised area
may be scar tissue formation rather than sign of persisting apical periodontitis
why do most failures occur
procedures havent reached a satisfactory standard for control and elimination of infection
pre-op factors affecting success
presence or absence of lesion
operative factors contributing to success
filling extended to 2mm of apex but not extruded
well-condensed root filling with no voids
good quality coronal restoration
technical complications leading to biological failure
coronal leakage, difficult to establish causality
other factors affecting outcome
presence of sinus, increased lesion size, no perforation, getting patency, penultimate rinse with EDTA, absence of flare up
how to improve success hit rate
centrality and concentricity
access and canal location
what are the laws of symmetry
1 - except maxillary molars, orifices of canals are equidistant from a line drawn in a mesial-distal direction through pulp chamber
2 - except from maxillary molars, orifices of canals lie on a line perpendicular to line drawn in a mesial-distal direction across centre of floor of pulp chamber
what is the law of colour change
the colour of the pulp chamber is always darker than the walls
what are the laws of orifice location
1 - orifices of root canals always located at junction of walls and floor
2 - orifices of root canals located at the angles in floor-wall junction
3 - orifices of root canals are located at terminus of root developmental fusion lines
apical patency
preparation technique in which apical region of canal is maintained as free of debris by recapitulating through apical constriction with a fine line
reasons for failure
iatrogenic (avoid creation of ledge), poor planning, poor access, poor length control, forcing instruments, failure to observe sequence, failure to maintain patency
