Endo Failure Flashcards
How is success defined
- ESE guidelines define a successful outcome
- Success means different things to researchers, clinicians and patients
- Technical vs biological outcome
What is a successful outcome according to ESE
○ Absence of pain, swelling and other symptoms
○ No sinus tract
○ No loss of function
○ Radiological evidence of a normal PDL
What is a uncertain outcome according to ESE
○ Radiographic changes remaining the same size or only diminished in size
○ 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 RCT is usually considered to be associated with post-treatment disease
What is an unfavorable outcome according to ESE
○ 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 retreatment is advised
When should RCT be checked
should be assessed at least after 1 year and subsequently as required
What are exceptions to unfavorable outcome
• An extensive radiological lesion may heal but leave a locally visible, irregularly mineralized area
• This defect may be a scar tissue formation rather than a sign of persisting apical periodontitis
The tooth should continue to be assessed
What is the issue with determining success
• Means different things to different people
A greater success rate is seen in those with a looser criteria e.g for some simply retention alone was considered successful in which the success rate was 95%
What leads to failure
Most failures occur when tx procedures mostly of a technical nature, have not reached a standard satisfactory for the control and elimination of infection
What are the 4 factors that are leading to failure
pre-op
operative factors
technical complication leading to biological failure
additional factors
What are pre op factors
§ Presence or absence of lesion
□ Vital has best outcome
□ Non-vital without periapical lesion has better prognosis than one with a periapical lesion
What are the operative factors contributing to success
□ Filling extending to within 2mm of radiographic apex
® If short may indicate that disinfection is not adequate and a good apical seal is not created so the outcome is diminished
□ Filling not extruded
® Extrusion = bad outcome
® Apical constriction may be destroyed
□ Well condensed root filling with no voids
Good quality coronal restoration
What is a technical complication leading to biological failure
Coronal leakage due to failure of coronal seal
What are the additional factors that contribute to success
□ Presence of sinus
□ Increased lesion size
□ No perforation
□ Getting patency
□ Penultimate rinse with EDTA (especially with retreatment)
□ Avoiding mixing chlorhexidine and sodium hypochlorite
Absence of flare up
What are the factors that contribute to success
finding all canals
achieving and maintaining latency
avoiding creation of ledges (iatrogenic)
avoid separation of instruments (iatrogenic0
What leads to creation of ledges
§ Poor planning § Poor access § Poor length control § Forcing instruments § Failure to observe sequence Failure to maintain patency
What are the laws for pulp chamber floor anatomy
law of centrality
law of symmetry
law of color change
law of orifice location
What is law of centrality
○ Pulp chamber lies central within the tooth at the level of the ACJ and lies concentric to the surface of the tooth at the level of the ACJ
Undulations of the root canal match that of the root surface at the level of the ACJ
What is the 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
What is the 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
What is the law of color change
The colour of the pulp-chamber floor is always darker than the walls
What is the law of orifice location I
§ The orifices of the root canals are always located at the junction of the walls and the floor
What is the law of orifice location II
§ The orifices of the root canals are located at the angles in the floor-wall junction
What is the law of orifice location II
§ The orifices of the root canals are located at the terminus of the root developmental fusion lines
§ These dark lines lead us to the orifice at each of the corners
What are biological reasons for failure
persistant intra-radicular infection extraradicular bacteria non microbial agents cholesterol crystals foreign body reactions which delay healing scar tissue healing
What are the persistent intra radicular infection due to
○ Canal complexities
○ Biofilm
○ Resistant bacteria
Enterococcus faecalis has been identified but role is controversial
What are non microbial agents
○ Cyst formation - epithelial lines cavities
Developed from mature granuloma, inflammatory mediators acting on epithelial cell rests
What is the periapical cysts
• Split in the literature into true and pocket cysts
○ True = separate from root canal
○ Pocket = continuous with it
• Prevalence varies in the literature but best evidence is approx. 15%
Is therapy required for cysts
• Granulomas, abscesses or cysts are primarily caused by root canal infection, we should use a treatment protocol that will eliminate their aetiology in the root canal system rather than their product
A granuloma or pocket cyst will resolve but a true cyst will not so may require surgical intervention
How do we decide on retx
• Decision making process depends on an accurate diagnosis
• Establish the cause of failure
○ Technical e.g perforation/separated instrument
○ Root fracture
○ Other odontogenic pain
Non odontogenic pain e.g atypical facial pain
How do we decide on assessing restorative prognosis
• Check for presence of fractures - need good magnification and illumination
• Assess remaining amount of tooth structure
Can you get a good seal and will the restoration last
What are options for pretreatment planning
○ Keep under observation
§ Need to have conversation with patient to figure out the cause
§ If a non odontogenic cause e.g malignant change in periradicular tissues then may want to move to other tx
○ Orthograde retreatment
○ Surgical treatment
§ Removing periradicular tissues, root tip and creating a seal from the apical region up
○ Extraction
What is the best outcome for failure
- Already seen that most failures due to inadequate disinfection of the root canal system initially, leaving residual bacteria
- In most causes therefore, non-surgical retreatment will offer best outcome
How do we determine complexity of re tx
- If the original anatomy has not been damaged, the complexity of the treatment is not high
- If there are fractured instruments, blockages, ledges, severe curvatures, it is more complex and so consider referral
- Apical surgery is complex and considered a specialist treatment - consider referral
