The concepts of success and failure in endodontics are often relegated to positions of secondary importance. lets talk about this.

1. ENDODONTIC
FAILURES
Presentation By:
Garima Singh
1

2. Content
• Introduction
• Historical and contemporary views on success and failure
• Factors influencing success or failure
• Evaluation of success / failure
Clinical evaluation
Radiographic evaluation
Histological evaluation
Influence of microbial factor in success/failure
• Interpretation of evaluative factors in determination of success/
failure
• Establishing a differential diagnosis of endodontic failure
• conclusion 2

3. Introduction
• The concepts of success and failure in endodontics are often
relegated to positions of secondary importance.
• This is evident in textbooks, in which chapters on these issues, if
present, are situated deep into the written material, where as
those chapters that deal with canal cleaning and shaping,
obturation, surgery, and so forth are in forefront.
3

4. •Many aspiring professionals are never faced with the
concepts of success and failure in didactic courses, and
certainly not in clinical training:
In a requirement-driven curriculum, success is
erroneously assumed once treatment is completed.
4

5. •The dental professional is faced with a daily continuum
of clinical situations requiring an integration of facts,
experiences, interpretation, applications, and analyses.
•The ability to confront these situations in a systemic and
successful manner characterizes the problem-solving
approach to treatment and evaluation.
5

6. Historical and contemporary views on
success and failure
• Historically the concept of success or failure of endodontic
therapy has centered on the “sterilization” of root canal
system, coupled with the perceived need to achieve a
hermetic apical seal.
• Both research and clinical studies focused on these issues as
the priorities in successful treatment.
6

7. 7

8. •A more through understanding of pulpal and
periradicular disease processes indicates that the key to
success in endo therapy is the debridement and
neutralization of any tissue, bacteria, or inflammatory
products within the root canal system .
8

9. Factors that will influence success or
failure in all cases
•Radiographic interpretation,
•Anatomy of the root canal system and external root,
•Thoroughness of debridement and apical level of
instrumentation,
9

10. •Degree of apical seal,
•Degree of coronal seal and quality of coronal
restoration,
•Operator skill and expertise
10

11. Evaluation of success and failure
•Success or failures following endodontic therapy could
be evaluated from combination of
Clinical criteria,
radiographical criteria and,
Histopathological criteria.
11

12. Clinical evaluation for success & failure
12

13. •If retention of the tooth in symptom-free clinical
function is the aim of endodontic therapy, then many
cases can be classified as clinically acceptable using
previous criteria.
13

14. •The use of the term ‘ adequate clinical function’ may be
more realistic, if retention of the tooth in function is the
ultimate aim of treatment.
14

15. •nevertheless, ultimate success or failure must identify a
middle ground where the integration of all factors-
clinical, radiographic, histologic and their ultimate
effects can be recognised and accepted.
15

16. Overfilling of gutta-perhca, n loss of
root curvature
After 3 yrs: resolution of periapical
pathosis and reformation of sound
lamina dura and pdl space
16

17. •However, despite the assessment of all these factors,
failure will at times occur, and a realistic perspective
must be maintained.
•In all cases, neither the presence nor absence of clinical
symptoms alone should determine the success or failure
of a case without integrating other factors.
17

18. Radiographic evaluation for success &
failure
•The radiographic evaluation of the periradicular
tissue is highly dependent on subjective evaluation
and interpretation.
•Objective criteria for treatment have been
published by American Association of Endodontists
(AAE) in their Quality Assurance Guidelines.
18

19. “radiograph should show a dense, three-dimentional filling
that extends as close as possible to the cementum- dentin
junction.”
19

20. •These criteria can be classified into three categories:
Radiographically acceptable
Radiographically questionable
Radiographically unacceptable
20

21. Radiographically acceptable
•Normal or slightly thickened (<1 mm)periodontal
ligament space
•Reduction or elimination of previous radiolucency
•No evidence of resorption
•Normal lamina dura
•A dense three dimensional obturation of canal space
21

22. Premolar classified as unacceptable, fiest molar as acceptable, and 2nd
molar as questionable
22

23. Radiographically questionable
• Increased pdl space ( <2mm)
• Radiolucency of similar size or slight evidence of repair
• Irregularly thickend lamina dura in relation to adjacent teeth.
• Progressive resorption
• Voids in density of canal obturation, especially in apical third of
canal
• Extension of filling material beyond the apex.
23

24. Maxillary 2nd
premolar: viewed as
acceptable by one practitioner and
unacceptable by other
24

25. Radiographically unacceptable
• Increased width of pdl space (>2mm)
• Lack of osseous repair within a periradicular rarefaction , or
increase in size of radiolucency
• Presence of osseous radiolucency in perradicular areas
where previously none existed, including lateral
radiolucencies.
25

26. •Visible patent canal space/ voids in canal obturaiton
•Excessive overextension of filling material with obvious
voids in apical 3rd
of canal
•Definitve evidence of progressive resorption
26

27. Failure to clean and shape the
canal system , poor obturation
and presence of broken
instrument in middle of the canal
27

28. •The determination of success or failure based solely on
radiographic criteria is ill advised, because clinical
findings must be included in the decision- making
process.
28

29. Histological evaluation for success/ failure
•Histological assessment of success and failure is
relatively meaningless in the clinical practice of
endodontics.
•Several studies have supported the concept; apparently
patients can exist in a state of chronic inflammation
without measurable symptoms.
29

30. •This state may be common in patients placed in the
clinically or radiographically questionable categories in
as much as vague symptoms may occur, coupled with a
slightly increased periodontal ligament space or a lack of
complete osseous repair as viewed on a radiograph.
30

31. •As an aid to clinician, histologic criteria of assessment
are listed to facilitate an understanding of the nature of
periradicular tissues when treatment evaluation is
questionable or unacceptable.
31

32. •Acceptable criteria:
Absence of inflammation
Regeneration of periodontal ligament fibers
Presence of osseous repair
Absence of resorption
Repair of previously resorbed areas
32

33. Influence of Microbial factor in success /
failure
•In a study of monkey teeth, Möller et al. (1981)
demonstrated that only devitalized pulps that were
infected induced periradicular lesions, whereas
devitalized and uninfected pulps showed absence of
pathological changes in the periradicular tissues.
33

34. •Sundqvist (1976) confirmed the important role of
bacteria in periradicular lesions in a study using human
teeth, in which bacteria were only found in root canals of
pulpless teeth with periradicular bone destruction.
34

35. • If microorganisms persist in the root canal at the time of
root filling or if they penetrate into the canal after filling,
there is a higher risk that the treatment will fail
(Byström et al. 1987, Sjögren et al. 1997).
35

36. •The chances of a favourable outcome with root canal
treatment are significantly higher if infection is
eradicated effectively before the root canal system is
obturated.
36

37. •How high the risk of reinfection will be is dependent on
the quality of the root filling and the coronal seal
(Saunders & Saunders 1994)
•In most cases, failure of endodontic treatment is a result
of microorganisms persisting in the apical portion of the
root canal system, even in well-treated teeth.
37

38. •To survive in the root-filled canal, microorganisms must
withstand intracanal disinfecting measures and adapt to
an environment in which there are few available
nutrients.
38

39. • Studies have reported the occurrence of viable
microbial cells in treated teeth with a persistent
periradicular lesion indicates that microorganisms derive
nutrition, presumably from tissue fluid which can seep
into the root canal space (Sjögren 1996, Sundqvist et al. 1998,
Molander et al. 1998).
39

40. •Failure of endodontic treatment attributed to remaining
microorganisms will only occur if they possess
pathogenicity, reach sufficient numbers, and gain access
to the periradicular tissues to induce or maintain
periradicular disease.
40

41. •Möller (1966), after examining failed cases, reported a
mean of 1.6 bacterial species per root canal. Anaerobic
bacteria corresponded to 51% of the isolates.
Enterococcus faecalis was found in 29% of the cases.
41

42. •Sundqvist et al. (1998) observed a mean of 1.3 bacterial
species per canal and 42% of the recovered strains were
anaerobic bacteria. E. faecalis was detected in 38% of
the infected root canals.
•E faaecalis is the pathogen of significance in most cases
of failing endodontic treatment.
42

43. Integration of evaluative factors in
determination of success and failure:
•The clinician is frequently required to assess the success
of previously completed endodontics treatment to
identify and manage teeth that exhibit signs and
symptoms of pulpal and periradicular pathosis.
43

44. The evaluation of previous endodontic
treatment during routine examination
•Research and successful clinical experience indicate that
endodontic therapy is most successful when the root
canal system has been thoroughly cleaned to the apical
construction and sealed.
44

45. 21 month follow up
radiograph
Angled view of the
obturation showing
the entire canal
system
Immediately
following RCT
Mandibular incisor,
bifurcation of canal at
midroot level (arrow)
45

46. •In case of root canal fillings that terminate 2mm or more
from the radiographic apex, it is obvious that there may
be uninstrumented and unfilled canal space, which are a
potential cause of failure.
46

47. Maxillary molar with RCT. Tooth was symptom free. All canal
were filled far short of the ideal apical position. Long-term
prognosis is questionable.
47

48. • Root canals filled with pastes, silver cones, or other materials
have questionable success rates as compare with well
condensed gutta-percha.
Multiple maxillary posterior teeth with a history of paste-filled root canals at
least 5 yrs before this radiograph. All teeth are symptom free. 48

49. •The presence of these former materials in symptom free
teeth represents a significant potential for failure
because their removal in retreatment situations almost
invariably show evidence of a poor seal.
49

50. •Often a symptom free , grossly carious tooth exhibits
apparently successful root canal treatment.
Maxillary premolar showing
extensive coronal destruction
Radiograph of same tooth: shows RCT of
acceptable quality, there is a periradicular
radiolucency
50

51. •Although it might be
assumed that the canal
seal is adequate, numerous
studies indicate that the
seal is as vulnerable to
failure from coronal
leakage .
A demineralized and cleared tooth specimen of an extracted
tooth showing leakage staining from the pulp chamber to the
root apex. Note the apical sealing (arrow) that did not stop
the leakage pattern
51

52. •It would be unwise to proceed to the restoration of any
tooth which the endodontic filling has been exposed to
saliva for an extended period of time.
52

53. Establishing a differential diagnosis of
endodontic failure: percussion tenderness
•It is not unusual to receive a patient referral with a
diagnosis of endodontic failure, only to find on
examination that the endodontic treatment is
satisfactory.
53

54. •The signs and symptoms of endodontic failure usually
originate in the periradicular tissues.
•Swelling , tenderness to palpation or percussion and
development of or increase in a periradicular lesion are
common.
54

55. • There are only three potential causes for percussion tenderness:
Recent trauma
Occlusal trauma
Endodontic failure
55

56. •Recent trauma:
Easy to diagnose, and percussion tenderness alone would
be expected to resolve gradually without specific
treatment, as long as the tooth is not on abnormal
occlusion.
56

57. •Occlusal trauma
A tooth in occlusion in which there is tenderness to
percussion and there has been no injury.
Occlusal abnormalities should be considered when there is
evidence of bruxism or wear facets.
57

58. Extreme occlusal wear consistent with bruxism
58
Occlusal wear facets on a mandibular molar

59. •Failing root canal treatment
A root canal treated tooth remains percussion tender 2
weeks after elimination of occlusal contacts or presents
initially without an opposing tooth.
59

60. •Assuming that examination with the periodontal probe
has ruled out fracture and the root canal treatment is
not recent , the diagnosis of endodontic failure is
probably in order.
60

61. •Since it is not unusual to observe percussion tenderness
in a recently completed endodontic case, diagnosis of
failure would be premature.
61

62. •Likewise, since the periradicular inflammation
associated with failure is due to loss or lack of an apical
seal, or remnants of tissue debris, symptoms of failure
do not usually appear until months after completion of
treatment.
62

63. Establishing a differential diagnosis of
endodontic failure- discomfort to thermal
stimulus
•Discomfort to a thermal stimulus without exception
requires the presence of dental pulp tissue in the tooth
that hurts.
63

64. •In a clinical situation in which the patient complains of
thermal sensitivity or discomfort originating from an
endodontically treated tooth, only two possibilities
exist:
Untreated canal in the endodontically treated tooth.
Discomfort originates from another tooth.
64

65. Establishing a differential diagnosis of
endodontic failure: radiographic signs of
endodontic failure
•interpretation of minimally widened apical periodontal
ligament space,
•Interpretation of a periradicular lesion on a tooth with
prior endodontic treatment.
65

66. Interpretation of minimally widened
apical periodontal ligament space
•There are three possibilities that may exist
A normal PDL space superimposed over an anatomic void
in the bone.
Other common examples are superimposed over the
mandibular canal, the incisive canal foramen, or a cystic
cavity caused by another tooth. 66

67. Two endodontically treated maxillary posterior teeth with apices near or above the sinus
floor.The molar appears to have a widened apical periodontal ligament space. This is
normal. The premolar has a periradicular lesion.
67

68. •A periradicular lesion
may be developing from
failing root canal
treatment.
Maxillary lateral incisor with poor quality RCT.
The widened PDL space is evidence of pathosis
68

69. •Scar tissue may be present after the healing of a
periradicular radiolucency.
25month revaluation radiograph.
69
Periradicular lesion is noted
at the apex of a mandibular
incisor:
immediately following
obturation ,

70. •In all three cases, without a history of symptoms and
without clinical signs of pathosis , the best course is to
wait and observe the area.
•If symptoms or clinical signs of pathosis reappear at any
time, revaluation would be indicated.
70

71. Interpretation of a periradicular lesion on
a tooth with prior endodontic treatment
•All three possibilities discussed previously exist as for
the previous problem, superimposition over normal
structures is found much less frequently, since only a
large foramen would have the approximate shape of an
apical lesion.
71

72. • Healing lesions could also
be ruled out as a
possibility if the tooth is 2
yrs after treatment.
A large periradicular lesion on a mandibular
central incisor. Root canal treatment was
completed with a silver cone, 18yrs earlier
72

73. •In the distinct majority of endodontically treated teeth,
the presence of periradicular lesion represents failure for
which surgical retreatment would be the treatment of
choice.
73

74. Interpretation of very large periradicular
lesion associated with the apex of an
endodontically treated tooth
•Occasionally a normal sinus might be misinterpreted as
a large periradicular lesion.
74

75. •If a large lesion has no symptoms and no evidence of
drainage , a biopsy might be indicated if normal
anatomy cannot account for the radiographic
presentation.
75

76. •It is uncommon but not impossible for a large
periradicular lesion to develop from an endodontic
failure.
Large periradicular lesion associated
with failing RCT on mandibular molar
Reevaluation 7 months after
nonsurgical retreatment
76

77. •Lesions of nonpulpal origin must always be suspected,
and a biopsy to provide a differential diagnosis may be
indicated.
77

78. Interpretation of radiographic lesions
enveloping an entire root
•Lesions that appear to involve significant bone loss
limited to a single root and extending to the crest of
bone should be suspected of having a sever periodontal
defect, a vertical root fracture of a failing RCT that
would be capable of healing.
78

79. A periradicular radiolucency enveloping the entire distal root
of mandibular 2nd
molar. Periodontal probing was consistent
with advanced periodontal disease
79

80. •It is more difficult to reach a diagnosis of advanced
periodontitis where such a lesion seems to be solitary.
•In term of prognosis, however, if the probing pattern
confirms deep pocketing and loss of attachment over a
wide area of the root circumferentially, the prognosis is
nearly hopeless regardless of the cause.
80

81. Establishing a differential diagnosis of
endodontic failure: clinical signs of
pathosis
•Clinical signs of pathosis associated with endodontic
problems generally result from infection.
•Other causes are a periodontal lesion, a vertical root
fracture and a lesion arising from an adjacent tooth.
81

82. • Most vertical root fractures occur on the buccal or lingual of the
root; consequently, radiographic changes are often absent.
• When bone destruction associated with a vertical root fracture is
sufficient to cause radiographic changes, the periodontal
ligament will usually appear distinctly and uniformly widened
around the entire root to the crest of bone.
82

83. Bone loss around a mandibular premolar consistent with a vertical root
fracture . This was confirmed with probing
83

84. •If on the same endodontically treated root the clinician
finds both a mucosal sinus tract and a narrow vertical
probing pattern the diagnosis will always be vertical root
fracture.
84

85. Deep narrow probing defect over the buccal
aspect of distal root, note the sinus opening on
the mucosa
Radiograph of same tooth, showing
no apical lesion.
85

86. Draining mucosal sinus tract associated
with an endodontically treated tooth
•Assuming the probing is normal, there are two
radiographic possibilities:
A radiographic lesion
The absence of radiographic lesion
86

87. •Only exploratory surgical tissue reflection will reveal the
exact cause .
•Other possibilities are
Post perforation
Retentive pin perforation
Root fracture
87

88. •If there is radiographic evidence of bone loss, the
location of the radiolucency will give a clue to the cause.
•Apical lesions will most likely be the result of endodontic
failure.
88

89. •If a 2nd
canal is likely and radiographs exposed from
different angles are not helpful, the tooth should be
reopened for retreatment.
•It is sometimes possible to treat only an untreated canal
without retreating the filled canals.
89

90. •A midroot radiolucency presents various possibilities. If
the root is straight and the canal appearance does not
suggest perforation, a lateral canal could be the cause.
90

91. Surgical exposure reveals a lateral lesion.
Radiograph of same tooth:
Apical PDL space is minimally widened
91
Draining sinus tract over lateral incisor

92. •There is no effective treatment for a midroot
perforation.
•Root resection or tooth extraction is often indicated.
92

93. Summery : causes of endodontic failures
93

94. Conclusion
•Determination of endodontic failure in absence of
symptoms is difficult. In most cases where accurate
diagnosis is not possible , a wait and watch approach is
best.
94

95. •The clinician who performs endodontic therapy must
understand the level of diagnosis, treatment planning
and treatment necessary to achieve success and to
attain that level on a consistent basis.
95

96. References
• Siqueira JF.Aetiology of root canal treatment failure: why well-treated teeth can
fail. Int endo J. 2001; 34: 1–10.
• Gutmann JL , Dumsha TC, Lovdahl PE, Hovland EJ. Problem solving in
endodontics. In: Gutmann JL, Lovadahl PE, editors. Problems in the assessment of
success and failure, quality assurance and their integration into endodontic
treatment planning. 3rd
ed. USA: Mosby Publications; 1997. p. 1-22.
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97. Thank you 97