Management of Endodontic Failure Flashcards
Aim Endodontics tx?
Prevent/ cure periapical periodontitis
How assess outcome of endo?
Has aim been met - absence/ resolution periapical periodontitis
Strict sign of success?
No symptoms, no clinical sign disease and no PA radiolucency
Loose sign of success?
No symptoms and no clinical sign of disease
Decrease (no increase) size pre-op PA lucency
Best way to grade outcome of endo success?
Favourable
Uncertain
Unfavourable
What does survival of tooth mean?
Tooth present in arch and is asymptomatic and functional
Main 3 factos affect endo success?
- Pre-op status PA tissue
- Quality root canal filling
- Quality coronal restoration
What makes success more likely when considered pre-op status PA tissue?
Vital pulp - pulpitis/ necrotic but uninfected
Success = 95%
What sign when assessing pre-op status PA tissue would make success less likely?
Periapical periodontitis - PA radiolucency
Because canal heavily infected
Success = 85%
Does size of PA radiolucency affect success?
If larger 5mm diameter further reduction chance success
What defines a good quality root filling?
Extends within 2mm of apex and is well compact
What decrease chance of success when assessing filling?
Overextended/ underextended
Voids in filling
What looking for in coronal restoration?
No marginal deficiencies/ defects/ recurrent caries -route for bacteria to re-infect
Best coronal restoration provide post-RCT?
Full-coverage
Why are full-coverage restoration adv after RCT?
Improve coronal seal
Improve structural durability
When should success RCT be assessed?
9-12 months following - clinical and radiographic assessment
Earlier if continued symptomas
Should new PA be taken less 9-12 months if pt have symptoms?
Only if suspect further dx e.g root fracture
How long should RCT be assessed for?
Depending outcome of review up to 4 years
What symptoms should ask pt about when assessing RCT?
Pain, swelling and function
Does lack of symptoms = success?
Not always
What are other reasons for symptoms if RCT not unfavourable?
Occlusal interferences
Food trapping
Tooth fracture
Neurogenic pain
What should be assessed in clinical exam?
Look swelling/ sinus tract Tenderness palpitation soft tissue Tenderness percussion of tooth Presence fractures Presence caries Periodontal status - depth/ mobility Quality restoration
What assess post-op radiograph?
Quality filling Presence/ absence PA lucency Size PA lucency - compare pre-op Quality restoration Caries and perio
When would CBCT be indicated to assess RCT?
Persistent pain w/ no sign conventional radiograph
What is favourable outcome?
Symtom free
Functional tooth
Clinically associated tissue health
Radiograph - PA tissues healthy
When is there an uncertain outcome?
No signs or symptoms
BUT
Radiograph - PA lucency persist - same size/ reduced within 4 year assessment period
When is outcome unfavourable?
Pt symptoms
Tooth not functional
Clinical sign infection
Radiograph: new lucency, increase size lucency, lucency persisted at/after 4 year assessment
How does outcome affect further review?
Review 9-12 months
Favourable - no further review
Uncertain - annual review 4 years
Unfavourable = further tx
When should indirect restoration be placed?
After resolution clinical signs and symptoms
Don’t need wait resolution radiographic lesion
4 reasons endo can fail?
Intraradicular infection
Extraradicular infection
True cyst
Foreign body reaction
What is intraradicular infection?
Persistant infection due residual microbes left in canal
or microbes re-enter (due coronal leakage/ fracture)
What can cause extraradicular infection?
Periapical actinomycosis
Why can endo fail due cyst?
Apical cysts are self sustaining and won’t heal with satisfactory RCT
How assess outcome RCT if you didn’t do it?
Hx - where and when performed
Ideal if have original diagnosis
Did tx initially remove symptoms
What technique used - was rubber dam used, hypochlorite etc
4 main options if endo failed?
No tx - monitor
XLA
Endo re-tx
Apical surgery
What should pt be advised if endo fail and have decided no further tx?
Tooth will require regular review
To return if signs/ symptoms develop
Acute flare up may occur
When are XLA considered after failure RCT?
Pt doesn’t wish have further tx
Tooth restorability doubtful
Non-functional tooth w/ no strategic value
Untreatable disease - root fracture/ advanced bone loss
What is tx of choice if have post-tx disease and pt keen to save tooth?
Endo re-tx
What must a tooth be to consider re-tx?
Restorable
Is success of re-tx good?
Success = 80%
Success normal RCT = 83%
What should pt be advised of prior re-RCT?
Tooth may be deemed unrestorable - fracture/ gross caries
Complex w/ associated risks - perforation, unable instrument canal
When can surgical endo be carried out?
Not possible to carry out re-rct
Indications surgical endo (re-tx)?
Re-RCT would be unfavourable
Obstructions in canal can’t be removed/ negotiated
Posts - risk fracture if removed
Perforation - need surgical repair
Investigative procedure - biopsy/ confirmation fracture
True cyst
What does endo-re-tx comprise of?
Removing content canal following by disinfection and cleaning
Can include repair perforation
What are ways to remove GP?
GG bur followed hand file (K and H files)
Re-tx rotary NiTi
Solvent technique
How are GG and hand files used in re-tx?
GG removes coronal GP
Hand files remove apical GP
Use tactile sensation of rubbery GP
Why use hedsrom files for re-tx?
Grip GP as it engages in the cutting flutes
Adv using rotary NiTi re-tx files?
More resistant fracture and dislodge GP coronal direction
Examples of solvent?
Chloroform, eucalyptus and orange oil
Ideal time to use solvent?
Following bulk removal
How can endo posts be removed?
Use ultrasonic - break cement lute
Using fine forceps
Post removal kits
Stage of removing endo post?
Remove crown and core material - leave post
Loosen post
How remove threaded post?
Can often be unscrewed
What technique can be helpful to remove therma-fil carriers?
Using braiding technique - braid.2 hand files around carrier
Issue with silver points?
Corrode over time - can disintegrate during removal
What changes success of removal fractured instrument?
Where instrument fractures What type instrument it is How long fragment is Accessibility Ability bypass if can't be removed
How remove fractured instrument?
Good access and vision - microscope
Use ultrasonic/ modified GG
What assess when perforation made?
Size
Location
Condition remaining tooth
Types of perforation?
Internal and external
Choice of material for repair perforation?
MTA
Biodentine
What are pt options in general practice for re-tx?
Refer to dentist - specialist/specialist interest - private
Refer hospital - not all will accept
