Textbook reading endodontic failures and retreatment

1
Textbook readingendodontic failures and
retreatment
2
Introdution

• In different studies success rate ranges from 54
  percent to 95 percent.
• The definition of success is ambiguous
• - stringent radiographic and clinical
  normalcy
• - lenient only clinical normalcy

3
Endodontic treatment outcome

• Healed
• both clinical and radiographic presentations
  are
• normal
• Healing
• its a dynamic process, reduced radiolucency
• combined with normal clinical presentation
• Disease
• No change or increase in radiolucency,
  clinical signs
• may or may not be present or vice versa

4
Evaluation of success
5
Evaluation of success

• A clear definition of what constitute a failure
  following endodontic therapy is not yet clear.
• Success or failures following endodontic therapy
  could be evaluated from combination of clinical,
  histophthological and radiographical criteria.

6
Clinical evaluation for success

• No tenderness to percussion or palpation
• Normal tooth mobility
• No evidence of subjective discomfort
• Tooth having normal form, function and aesthetics
• No sign of infection or swelling
• No sinus tract or integrated periodontal disease
• Minimal to no scarring or discoloration

7
Radiographic evaluation for success

• Normal or slightly thickened periodontal ligament
  space
• Reduction or elimination of previous rarefaction
• No evidence of resorption
• Normal lamina dura
• A dense three dimensional obturation of canal
  space

8
Histological evaluation for success

• Absence of inflammation
• Regeneration of periodontal ligament fibers
• Presence of osseous repair
• Repair of cementum
• Absence of resorption
• Repair of previously resorbed areas

9
Causes of the endodontic failures

• Bacteria somewhere in the root canal system
• Divided into local and systemic

10
Factors affecting success or failure of
endodontic therapy in every case

• Diagnosis and the treatment planning
• Radiographic interpretation
• Anatomy of the tooth and root canal system
• Debridement of the root canal space
• Asepsis of treatment regimen
• Quality and extent of apical seal
• Quality of post endodontic restoration
• Systemic health of the patient
• Skill of the operator

11
Factors affecting success or failure of a
particular case

• Pupal and Periodontal status
• Size of periapical radioleucency
• Canal anatomy
• Crown and root fracture
• Iatrogenic errors
• Occlusal discrepancies if any
• Extent and quality of the obturation
• Quality of the post endodontic restoration
• Time of post treatment evaluation

12
Local Factors causing endodontic failures

• Infection
• Incomplete debridement of the root canal system
• Excessive hemorrhage
• Chemical irritants
• Iatrogenic errors

13
Infection

• infected and necrotic pulp tissue?main irritant
  to the periapical tissues
• The host parasite relationship?virulence of
  microorganisms?ability of infected tissues to
  heal?influence the repair of the periapical
  tissues
• Endo success ?
• debridement

14
Incomplete debridement of the root canal system

• Main objective of root canal therapy?complete
  elimination
• of the microorganisms and their
• byproducts
• Poor debridement ? residual microorganisms?byprodu
  cts and tissue debris ? recolonize

15
Excessive hemorrhage

• Extirpation of pulp and instrumentation beyond
  periapical tissues
• Local accumulation of the blood?mild inflammation
• Extravasated blood cells and fluidforeign body
  ?nidus for bacterial growth

16
Over instrumentation

• Instrumentation beyond apical foramen?PDL and
  alveolar bone trauma?the prognosis of endodontic
  treatment ?

17
Chemical irritants

• Intracanal medicaments and irrigating solution
• ?extruded in the periapical tissues?the
  prognosis of endodontic treatment ?
• Dont require medicaments(except in chronic
  inflammation )
• Using medicaments to avoid their periapical
• extrusion

18
Iatrogenic errors

• Separated instruments
• Caused by improper or overuse of
• instruments and forcing them in curved
• canals
• Prognosis no much affected in vital pulps
• poor in necrotic
  tissue (Seltzer et al)

19
Iatrogenic errors

• Canal blockage and ledge formation
• Accumulation of dentin chips or tissue debris
• ?prevent the instruments to reach its
• full working length
• Ledge formationstraight instruments in
• curved canals
• These lead to bacteria debris remained?
• endo failure

20
Iatrogenic errors

• Perforations
• Lack of knowledge of anatomy of the tooth,
• attention, misdirection of the instruments
• Prognosislocation, time, perforation seal
  andsize
• Poor prognosis ? remaining
• infected tissue

21
Iatrogenic errors

• Incompletely filled teeth
• Teeth filled more than 2mm short of apex
• Several studies shown
• poor prognosisunderfillings with necrotic
  pulps
• Overfilling of root canals
• Overfilling extending ?2mm beyond
• radiographic apex
• Continuous irritation of the periapical
• tissues? endo failure

22
Iatrogenic errors

• Anatomic factors
• Such asoverly curved canals, calcifications,
• numerous lateral and accessory
  canals,
• bifurcations, C or S shaped
  canals
• Problems in cleaning and shaping
• incomplete filling of
  root canals
• ? endodontic failure

23
Iatrogenic errors

• Root fractures
• Partial or complete fractures of roots
• Prognosis of teeth
• vertical root is poor than horizontal
  fractures
• Traumatic occlusion
• Cause endo failures because of its effect on
• periodontium

24
Systemic factors causing endodontic failures

• Nutritional deficiencies
• Diabetes mellitus
• Renal failure
• Blood dyscrasias
• Hormonal imbalance
• Autoimmune disorders
• Opportunistic infections
• Aging
• Long term steroid therapy

25
Endodontic retreatment

• Before going/performing
• Case selection
• Prognosis ,Contraindications and problems
• Steps

26
Before going to endodontic retreatment

• Treatment opportunity
• Patients needs expectations
• Strategic importance of the tooth
• Periodontal evaluation of the tooth
• Other interdisciplinary evaluation
• Chair time cost

27
Before performing to endodontic retreatment

• May to prevent the potential disease
• Remove/remade extensive coronal restoration
• Technical problems
• May not achieve better results
• Filling materials have to be removed
• Prognosis could be poorer
• Patient might be more apprehensive

28
Case selection

• Careful history - nature, pathogenesis, urgency
• Anatomy of root canal - canal curvature,
  calcifications, unusual configurations
• Quality of obturation
• Iatrogenic complications
• Cooperation of the patient

29
Factors affecting prognosis of endodontic
treatment

• Periapical radiolucency
• Quality of the obturation
• Apical extension of the obturation material
• Bacterial status
• Observation period
• Postendodontic coronal restoration
• Iatrogenic complication

30
Contraindications of endodontic retreatment

• Unfavorable root anatomy
• Untreatable root resorptions or perforations
• Root or bifurcation caries
• Insufficient crown/root ratio

31
Problems of endodontic retreatment

• Unpredictable result
• Frustration
• Cost factor
• Time consuming

32
Steps of Retreatment

• Coronal disassembly
• Establish access to root canal system
• Remove canal obstructions
• Establish patency
• Thorough cleaning, shaping and obturation of the
  canal

33
1. Coronal Disassembly

• Removal of existing coronal restoration

• Access made through coronal restoration

34

• Disadvantages of retaining a restoration

• Advantages of gaining access through original
  restoration

• Facilitate rubber dam placement
• Maintaining form, function and aesthetics
• Reducing the cost of replacement

• Reduce visibility and accessibility
• Increased risks of irreparable errors
• Increased risks of microbial infection if crown
  margins are poorly adapted

35

• Advice
• Remove the existing restoration
• Especially poor marginal adaptation, secondary
  caries
• Place temporary crown to maintain form, function
  and aesthetics.

36
2. Establish Access to Root Canal System

• Teeth restored with post and core
• Post and core need to be removed for gaining
  access to root canal system
• Post and core can be perforated to gain access

37
Posts can be removed by

• Weakening retention of
• posts by use of ultrasonic
• vibration.
• Forceful pulling of posts but it increases the
  risk of fracture
• Removing posts with the help of special pliers
  using post removal systems
• Occasionally access can be made through the core
  for retreatment procedure without disturbing the
  post.

38
Post Removal System(PRS)
39
Post Removal System(PRS)

• 5 various designed trephines
• Corresponding taps(microtubular tap)
• Torque bar
• Transmetal bur
• Rubber bumpers
• Extracting plier

40
1. Transmetal bur using

• Efficiently dooming of
• the post head

41
2. Add lubricant

• EX RC Prep
• Be placed on the post head to further facilitate
  the machining process

42
3. Trephine

• To engage the post
• To machine down the
• coronal 2-3mm of the post

43
4. Microtubular tap

• Inserted against the post head.
• Screwed it into post with counter clockwise
  direction.
• Rubber bumper inserting first.

44
5. Rubber bumper pushed down

• Pushed down to the occlusal surface

45
6. Post removal plier

• Mount the post removal plier on tubular tap
• Ultrasonic instrument using/torque bar inserting

Screw knob
Tubular tap
Rubber bumper
plier
46
Removing Canal Obstructions and Establishing
Patency
47
Silver Point Removal

• Microsurgical forceps
• Using ultrasonic

48
Silver Point Removal

• c. Using Hedstroem files(H-files)
• d. Using Hypodermic needle
• cyanoacrylate

49
Silver Point Removal

• e. Post removal system kit
• f. Using instrument removal system(IRS)

50
Gutta-Percha Removal

• The relative difficulty in removing gutta-percha
  is influenced by some factors of canal system
• Length
• Diameter
• Curvature
• Internal configuration
• Progressive Manner
• gutta-percha is best removed from canal in
  progressive manner to prevent its extrusion
  periapically

51
Gutta-Percha Removal

• Coronal portion of gutta-percha should always be
  explored by Gates-Gliddens to
• Quickly Remove gutta-percha quickly
• Solvent Provide space for solvents
• Convenience Improve convenience form
• Gutta-percha can be removed by using
• Solvents
• Hand instruments
• Rotary instruments
• Microdebrider

52

• 1. Solvents
• GP is soluble in
• Chloroformmost effective but carcinogenic ,
  excessive filling in pulp is avoided
• Methyl chloroform
• Benzene
• Xylene
• Eucalyptol oil
• Halothane
• Rectified white turpentine
• GP dissolution should be supplemented by using
  hand instruments

53

• 2. Hand Instruments
• Mainly in apical portion
• Hedstroem files
• Reamer or files can be used to bypass the GP
  sometimes.
• Overextended cones
• file have to be extended perically to avoid
  separation of the cone at the periapical region

54

• 3. Rotary Instruments
• Safe to be used in straight canals
• ProTaper universal system
• May , 2006
• Consisting of file D1 D2 D3
• 500-700 rpm

55
ProTaper universal system
56
Microdebriders

• A small files with 90 degrees bends
• Removing remaining gutta-percha on the sides of
  canal walls

57
Pastes and Cement

• Soft setting pastes
• Penetrated by endodontic instruments
• Hard setting cements
• Softened by solvents xylene, eucalyptol......
• Ultrasonic devices
• Long shank, small round bur

58
Separated Instruments and Foreign Objects

• Coronal third appempt retrieval
• Middle third appempt retrieval or bypass
• Apical third surgical treat

59
Separated Instruments and Foreign Objects

• Appempt retrieval
• Mechanism ? Stieglitz pliers, Masserann extractor
• Vibration ? Ultrasonics
• Accessibility ? Modified Gates Glidden bur
• Bypass
• Reamers or files with copious irrigation
• Surgical treat
• Apicoectomy

60
(No Transcript)
61
(No Transcript)
62
Completion of the Retreatment

• Thorough cleaning, shaping and obturation
• Some problems about retreatment
• Resistant microorganisms?Enterococcus faecalis
• Enlarged canal
• Restoration, post core......
• Overfilling, foreign objects, blockage,
  ledge......
• The outcome of retreatment
• Short-term no pain and swelling
• Long-term obturation of the root canal system
• Communication before treating