Endo Retx Flashcards
Reasons for Endo failure
- P erforation
- O bturation incomplete
- O verfill
- R oot canal missed
- P eriodontal reasons
- A nother tooth
- S plit tooth
- T rauma
T umor
A natomical variation
M icroleakage
Endo intraradicular infection def
– Microorganisms remaining in canal space, dentinal
tubules
Extraradicular infection def
– Bacterial plaque on external root surface (biofilm)
– Microorganisms in periradicular lesion (Actinomyces)
Leakage
– Inadequate coronal restoration
– Inadequate obturation
Resistant micro organisms associated with Endo Retx
– E. faecalis, Candida, viruses (?)
Causes of intra radicular infection
• Poor quality endo – Inadequate debridement – Inadequate irrigation – Improper WL • Missed canal • Instrumentation misadventure • Complex anatomy
Reasons for extraradicular infection
• Bacterial plaque (biofilm) on root-end • Bacteria in periradicular lesion (actinomyces) • Microorganisms associated with periodontium
Reasons for leakage
• Inadequate coronal restoration • Quality of coronal restoration may be “more important” than RCT • Inadequate obturation • Fractures – Incomplete crown fracture – Crown - root fracture – Vertical root fracture • Perforations
E Faecalis
– Binds to dentin – Invades dentinal tubules – Endures lengthy starvation – May survive calcium hydroxide
Criteria for end success
- Absence of pain or swelling
- Disappearance of fistula
- No loss of function
- No evidence of tissue destruction
- Radiographic evidence of eliminated or
arrested area of rarefaction after 6 to 24
months
Reasons for Retx of Asymptomatic teeth
• Further enlargement of apical lesion or no
evidence of any reduction in size
• Restorative tx planned on critical tooth
with questionable obturation
• Post space or retentive needs
• Exposure of gutta percha to the oral environment
Exposure of GP to oral environmenr
Studies vary from 1 wk to 90 days
• Gutta-percha does not form complete barrier
• Leaky and lost restorations, caries
– Bacteria can penetrate to apex in < 1 month
– Inadequate coronal seal may account for many
“endodontic” failures
• Retreat if ~ 1 month or greater exposure of
gutta-percha
– 0 - 1 month is “gray” area (retreat if unsure)
Cases w/ poor prognosis for NS ret
• Perforations (strip, furcal, or apical)
• Significant transportation or ledging
• Significant overfill
• Separated objects in apical canal space
• History of appropriate previous NS RETX
• Dilacerated roots and anatomical
variations
Inappropriate reasons for avoiding NS Retx
- Prefabricated posts
- Cast post and cores
- Solid core obturation material
- Amalgam retained core
- Radiographically well-obturated canal
Prognosis of NS ret
Retx always less % successful than initial
Good candidates
- Weak fill, visible space along and apical to fill
Rationale for
Non-Surgical RETX
• Relatively ‘easy’ – Access – Techniques easier to master • Theoretically more successful – Remove bacteria vs corking them inside • Clinically more successful? – Retreatment : > 80% – Surgery: ~ 70% Historic • Modern Techniques ~90%
Indications for Surgical TX
• Previous non-surgical retreat unsuccessful
• Blocked coronal approach or access problems
• Desire for apical inspection or biopsy
• Probability of non-surgical success deemed poor
(perf, ledge, etc)
• Monetary considerations (destruction of post, core, and
crown).
• Patient’s loss of trust in non-surgical approach
Contraindications for
Surgical RETX
- Patient’s medical health problems
- Lack of operator skills
- Patient’s inability to tolerate or accept surgery
- Anatomical considerations
- Non-surgical RCT has not been attempted