2. Objectives
Q1 - What is meant by the outcome of endodontic treatment?
Q2 - How do you classify the outcome of endodontic treatment?
Q3 - What factors influence the outcome of root canal treatment and retreatment?
Q4 - What factors influence the outcome of surgical endodontics?
Q5 - How do you assess the outcome of endodontic treatment?
Q6 - Why are the reported outcomes diverse?
3. الفشل و النجاح بتاع المثل
االندو و الجراحه بين مقارنه
Mayan Cosmetic Dentist
Scott Rice, Jewel Inlays by the Cosmetic Dentists of the Maya,
ricedentistry (949) 238-6745;2014
4. Progressive development of apical scar. This permanent artifact frequently follows through and-through osseous destruction of both labial
and palatal cortical plates. A Before cyst enucleation. B, Six months following surgery. C, One year following surgery. D, Two years
following surgery; scar is permanent. E, A similar nonpathologic radiolucent area was removed and examined; it is filled with fibrous
connective tissue, no inflammatory cells.
(A-D, Photos courtesy of Or M. Krasnoff; E, Photos courtesy of Dr. S,N. Bhaskar)
5. Q1 - What is meant by the outcome of
endodontic treatment?
8. Subjective terms, Ambiguous Terms
from the clinician’s point of view,
this endodontic treatment has clearly not been a success.
Case:
Q1 - What is meant by the outcome of
endodontic treatment?
An endodontically treated tooth
symptom free and functional,
with sinus tract and periapical radiolucency which is increasing in size,
The patient not experiencing symptoms and can use their tooth,
patient may call it,
SUCCESS
9. The Principles of Endodontics, By Shanon Patel, Justin J. Barnes
Q1 - What is meant by the outcome of
endodontic treatment?
1-No Symptoms.
2-No Clinical Signs Of Disease
3-No Periapical Radiolucency
Endodontic treatment to be deemed a success.
This is the ideal
However, it may be unrealistic to
achieve in all cases.
immediate post-
operative radiograph
showing a periapical
radiolucency
one year later
showing full
resolution of the
periapical
radiolucency
Strict/ Stringent
criteria:
10. - no symptoms,
- no clinical signs of disease,
- a decrease ( or at least no increase)
in the size of the preoperative
periapical radiolucency
The Principles of Endodontics, By Shanon Patel, Justin J. Barnes
loose/lenient
criteria:
This is a more realistic approach
- especially as it is currently not possible to
sterilize the entire Root canal system so
that it is microbe-free
Q1 - What is meant by the outcome of
endodontic treatment?
endodontic treatment to be deemed a success.
(a) immediate post –
operative
radiography:
(b) radiograph taken
one year later showing
a reduction in size of
the periapical
radiolucency .
11. patient being asymptomatic and able to use
the endodontically treated tooth.
“it doesn’t take into account whether
periapical periodontitis has been cured or
prevented following endodontic treatment.
Asymptomatic functional tooth “Functional retention”:
Similar to the dental implant assessment
criteria
Q1 - What is meant by the outcome of
endodontic treatment?
12. • Clinical normalcy with or without a persistent radiolucency, decreased or unchanged.
A- C, Mandibular first molar with apical periodontitis, associated with gingival recession, probing depth beyond the apex, and extensive bone
loss on the buccal aspect. The patient was advised of poor prognosis, but decided to proceed with treatment in an attempt to retain the tooth in
function as long as possible. D, E, Completed root canal treatment and application of a resorbable guided tissue regeneration membrane. F, G,
At 6 months, the radiolucency has been considerably decreased and the gingival tissue appears healthy, Although the prognosis remains poor,
the patient's goal has been achieved. Replacement of the defective crown has been deferred by the patient.
(Friedman 2002. )
Q1 - What is meant by the outcome of
endodontic treatment?
“Functional retention”
14. Healing, Disease, and Function – Clear Terms
Success is generally defined as ‘the accomplishment of an
aim or purpose’ (Oxford Dictionary).
The outcome, is best defined in direct relation to the
specific aim.
In the Endodontic ttt, the aim is to eradicate the disease and
allow healing.
Accordingly, in order to promote effective communication
within the profession and with patients, the outcome of
Endodontic Treatment should be related to ‘healing’
15. A combined clinical (no signs and symptoms) and radiographic (no residual radiolucency)
normalcy.
Included in this classification is the strictly defined, typical appearance of a scar.
Friedman 2002
Q1 - What is meant by the outcome of
endodontic treatment?
- Healed:
A, Maxillary second
molar with apical
periodontitis
extending along the
mesial root surface,
and associated sinus
tract (traced with a
gutta-percha cone)
B, Completed treatment. C, At 1 year, the
radiolucency is
completely resolved and
the tooth is symptom
free, indicating the
lesion has healed.
16. Reduced radiolucency combined with clinical normalcy, in follow-up periods shorter than 4
years. This is consistent with the strict definition of ‘uncertain’ healing.
Friedman 2002.
- Healing (in progress):
Q1 - What is meant by the outcome of
endodontic treatment?
A, Three
prefabricated posts
in mandibular
molar with post
treatment disease,
B, Access was
prepared through the
crown and posts were
removed: canals were
dressed with calcium
hydroxide
C, Completed root
canal re-treatment.
D, At 6 months, the
lesion is reduced and
the tooth is symptom
free, indicating that
healing is in
progress.
17. - Persistence of radiolucency (an expression of apical periodontitis) with or without clinical
signs and symptoms ,
- presence of symptoms even when the radiographic appearance is normal.
Friedman 2002.
Persistent disease “diseased”:
Q1 - What is meant by the outcome of
endodontic treatment?
A, Immediate post operative
radiograph of maxillary second
molar with no evidence of apical
periodontitis.
B, Emerged disease at 3 years. C, Further expansion of
disease at 6 years. In spite of
the presence of disease, the
tooth is symptom free.
20. Q2:How do you classify the outcome of
endodontic treatment?
21. •Patient symptom free
•The endodonticaly treated tooth is functional
•Clinically: The associated tissues are healthy
•Radiographicaly: the associated periapical tissue appear healthy or there is evidence
of healing by scare tissue formation.
Clinical evidence of a
favorable outcome
associated with a
mandibular lateral
incisor tooth (a)
preoperative sinus tract;
(b) the sinus tract healed
one year later
Q2:How do you classify the outcome of
endodontic treatment?
1-Criteria for a favorable outcome
22. •Patient may be complaining from symptoms or symptoms free
•Clinicaly: may be low grade tenderness to palpation or percussion
•Radiographically: periapical radiolucency has persisted (remind the same size or
only reduced in size) within the four year assessment period
Radiographic evidence of an uncertain outcome associated with
maxillary central incisor tooth
Q2:How do you classify the outcome of
endodontic treatment?
2-Criteria for uncertain outcome
(a) immediate
post operative
radiography
(b) radiograph taken one
year later shows no change
in the size of the periapical
radiolucency
23. •The patient is complaining of symptoms “pain , swelling”.
•The endodontically treated tooth not functional “the patient avoid eating on the tooth due to
aggravation of symptoms”
•Clinically: there are signs of infection, eg sinus tract, swelling.
•Radiographically:
-A new periapical radiolucency has developed post-treatment.
-the periapical radiolucency has increased in size post treatment
- the periapical radiolucency has persisted (remained the same size or only reduced in size) at
or after a four year assessment period.
Radiographic evidence of an unfavorable outcome
associated with a maxillary first molar tooth
Q2:How do you classify the outcome of
endodontic treatment?
3-Criteria for an unfavorable outcome:
(a)
immediate
post-
operative
radiograph
(b) radiograph taken one year
shows an increase in the size of
the periapical radiolucency
(yellow arrow)
25. Diagram summarizing the review process (Adapted from guidelines published by the European society of endodontology)
Q2:How do you classify the outcome of
endodontic treatment?
28. Factors that influence the outcome:
-Preoperative statues of the periapical tissue.
- Quality of the root canal filling
-Quality of the coronal restoration.
Factors that may influence outcome:
-Medical statues of the patient.
-Preoperative sinus tract statues.
-Experience of the clinician.
- Use of rubber dam.
- Type of files used for preparation.
- Type of irrigant used.
- Number of visits complete treatment.
- Type of medicaments used
- Type of root canal filling used
- Technique used to fill the root canal.
Factors that have no influence outcome:
-Gender of patient
- Age of patient
-Type of tooth
Q3:What factors influence the outcome of root canal treatment and
retreatment?
30. The outcome of endodontic treatment is more likely to be favorable in:
-teeth with vital pulps
- teeth with inflamed pulps(e.g. irreversible pulpitis)
-Teeth with necrotic uninfected pulps. 95%
Radiographically: these teeth would not have
signs of preoperative periapical radiolucency.
In teeth with signs of periapical periodontitis (i.e. periapical
radiolucency on radiography) the probability of achieving a favorable
outcome (i.e. curing an existing periapical periodontitis) after endodontic
treatment is in the region of 85 percent.
This is likely to be due to teeth affected by periapical
periodontitis having a more established infection
in the root canal system when compared to teeth
unaffected by periapical periodontitis.
1-Preoperative status of the periapical tissue:
85 %
Q3:What factors influence the outcome of
root canal treatment and retreatment?
31. The literature has conflicting
conclusions on the influence of the size
of the preoperative periapical lesion
on outcome of treatment.
The likelihood of a favorable outcome
appears to be higher when the size of the
preoperative periapical lesion is small
(<5mm).
Q3:What factors influence the outcome of
root canal treatment and retreatment?
32. 2-Quality of root canal filling:
Favorable outcome is lower when:
-the root canal filling is overextended “long”.
Microbes and infected debris are extruded into the periapical tissue.
Overextended root canal fillings and associated
periapical radiolucency.
It’s not necessary due to the overextended root
canal filling material itself.
Q3:What factor treatment s influence the
outcome of root canal and retreatment?
33. - The root canal filling is underextended “short”. This is because
the portion of the root canal which does contain any filling material is likely
to contain residual microbes due to inadequate mechanical and chemical
preparation.
Underextended root canal fillings with visible patent root
canal space apically and associated periapical
radiolucencies
Q3:What factors influence the outcome of
root canal treatment and retreatment?
34. -This is because spaces within the root canal filling may allow
periapical tissue fluid to enter the root canal and provide a nutrient of any residual
microbes,
a place for any residual microbes to multiply.
Passage of microbes and their toxins from the root canal space into the
periapical tissue.
Voids within root canal filling and associated
periapical radiolucencies
The root canal filling contain voids.
Q3:What factors influence the outcome of
root canal treatment and retreatment?
35. 3-Quality of the coronal restoration:
A satisfactory of the coronal restoration has no marginal deficiencies, defects, or recurrent
caries. Defects on the coronal restoration present routes for reinfection of the root canal space
from the mouth.
Unsatisfactory quality root canal fillings and coronal
restorations, and associated periapical radiolucencies
Q3:What factors influence the outcome of
root canal treatment and retreatment?
36. Factors that may influence outcome
Q3:What factors influence the outcome of
root canal treatment and retreatment?
37. Body’s ability to heal periapical periodontitis
may be impaired in certain medical
conditions.” Poorly controlled diabetes,
immunosuppressant medication”.
-Medical status of the patient:
Q3:What factors influence the outcome of
root canal treatment and retreatment?
38. May indicate a higher number or virulence of endodontic microbes.
There is some evidence to suggest that the probability of achieving a
favorable outcome is higher with no preoperative sinus tract.
-Sinus tract:
Q3:What factors influence the outcome of
root canal treatment and retreatment?
Ng Y-L, Mann V, Gulabivala K. A prospective study of the factors affecting outcomes of
nonsurgical root canal treatment: part 1: periapical health. International Endodontic Journal.
39. General dental practitioner
versus specialist in endodontics.
-Experience of the clinician
Q3:What factors influence the outcome of
root canal treatment and retreatment?
40. -Using of rubber dam:
Failure to use rubber dam has been shown to influence the choice of root canal irrigant, has a
negative impact on treatment outcome and places the patient at risk of swallowing or
aspirating materials and instruments.
Ahmad IA1, Rubber dam usage for endodontic treatment: a review. Int Endod J, 42(11):963-72 2009
Q3:What factors influence the outcome of
root canal treatment and retreatment?
41. Shanon Patel, Justin J. Barnes: stainless steel versus nickel titanium (NiTi), there are
many benefits to using niti file systems to prepare root canals, (reduce mechanical
preparation time, less clinician fatigue, however there is insufficient data to show that a
particular type of file will achieve a higher outcome of endodontic treatment.
-Type of files used for preparation
Q3:What factors influence the outcome of
root canal treatment and retreatment?
Gary S.P. Cheung, and Christopher S.Y. 2009 :Concluded that There was a higher
incidence of procedural errors and a lower success rate for primary root canal
treatment of teeth prepared with stainless steel files compared with the use of NiTi
instruments in a continuous reaming action
Gary S.P. Cheung, and Christopher S.Y. , A Retrospective Study of Endodontic Treatment Outcome
between Nickel-Titanium Rotary and Stainless Steel Hand Filing Techniques, J Endod 35:938–943,
2009
The Principles of Endodontics By Shanon Patel, Justin J. Barnes
42. irrigants which are antimicrobial and can dissolve organic materials has better outcome
“sodium hypochlorite (NaOCl) is the gold standard irrigant.
-Type of irrigant used:
Q3:What factors influence the outcome of
root canal treatment and retreatment?
43. New research suggest that there is no significant difference in the
outcome between single and multiple visit treatment.
-Number of visits to complete treatment:
Q3:What factors influence the outcome of
root canal treatment and retreatment?
Sathorn et al 2005:stated that single-visit root canal treatment appeared to be slightly
more effective than multiple visit, i.e. 6.3% higher healing rate. However, the
difference in healing rate between these two treatment regimens was not statistically
significant (P ¼ 0.3809).
C. Sathorn, P. Parashos & H. H. Messer, Effectiveness of single- versus multiple-visit endodontic treatment of teeth
with apical periodontitis: a systematic review and meta-analysis, International Endodontic Journal, 38, 347–355,
2005
no solid evidence to support one type of medicament over than another in term of
increasing the probability of achieving a favorable outcome.
-Type of inter-appointment medicament:
44. Gutta-Percha (GP), Polymer based materials, calcium silicate cements, in the 1990s there
was a flurry of literature purporting that GP leaked and polymer based materials were more
likely to seal the root canal system, the methodology and clinical relevance of these
mainly laboratory based studies has been criticized, presently, there is insufficient data to
suggest that one type of root canal filling material significantly increases the probability of
achieving favorable outcome.
-Type of root canal filing material used:
Q3:What factors influence the outcome of
root canal treatment and retreatment?
45. cold compaction, warm compaction, there are many pros and cons to the various root canal
filling technique.
-Technique used to fill the root canal system:
Q3:What factors influence the outcome of
root canal treatment and retreatment?
Chu CH, Lo ECM & Cheung GSP. Outcome of root
canal treatment using Thermafil and cold lateral
condensation filling techniques. International
Endodontic Journal, 38, 179–185, 2005
48. Outcome of surgical endodontics more likely to be favorable when using:
-Contemporary surgical equipment (micro-surgical instruments, operating
microscope, endoscope.
Q4: What factors influence the outcome of
surgical endodontics?
49. Contemporary techniques : resecting the root end without bevel, using
ultrasonic tips to prepare the root end cavity's.
Q4: What factors influence the outcome of
surgical endodontics?
53. Q5 - How do you assess the outcome of
endodontic treatment?
54. The most accurate way to examine the periapical area after
endodontic treatment by block dissection and serial
histological sections of the tooth and the surrounding jaw
bone
Q5:How do you assess the outcome of
endodontic treatment?
-Which is replaced by :
1-Assessment of the patient symptoms
2-Clinical examination
3-Radiographic examination
WHICH IS IMPOSSIBLE…!!!
(a) immediate post-
operative radiograph;
(b) radiograph taken one
year later shows bony
infill
55. Radiographic Outcome Assessment
Assessment of radiographic images has been shown to be highly inconsistent. The consistency
of assessment can be significantly improved when structured observer and calibration strategies
are applied, as suggested for endodontic treatment.
Goldman M, Pearson AH, Darzenta N. Reliability of radiographic interpretations. Oral Surg Oral Med Oral Pathol Oral Radiol Endod
1974:38:287-93
Q5:How do you assess the outcome of
endodontic treatment?
56. (b) radiograph taken 1 year
after treatment showing no
periapical radiolucences.
Patel S, Wilson R, Dawood A, Foschi F, Mannocci F (2012) the detection of periapical pathosis using digital periapical
radiography and cone beam computed tomography – Part 2: a 1- year post treatment follow-up, international
endodontic journal, 45,711-23,
(c) reformatted cone beam
computed tomography (CBCT)
images reveal no preoperative
periapical radioulucent but
(a)Preoperative
radiography of mandibular
left first molar tooth
(d) 1 year later, there are
new periapical radioluces
(as indicated by the arrows)
60. Case selection criteria
• The process of case selection involves the
differentiation of potential candidates for
treatment according to their prognosis;
therefore, it is likely to determine the results of
a clinical study .
In the majority of studies, cases were included
without specific inclusion or exclusion criteria.
• Therefore, the reported outcomes may have
been affected by inclusion of teeth with poor
prognosis.
Q6:Why are the reported
outcomes diverse?
61. Case selection : inclusion of teeth with a compromised
prognosis in the study sample.
If the sample of a clinical study includes many teeth
with a compromised prognosis, the healing rate is
lower than if such teeth are not included.
Skoglund A and Persson G.1985
Q6:Why are the reported
outcomes diverse?
62. Multi-rooted teeth – individual roots vs. the whole tooth as the evaluated
unit.
• The whole tooth was the evaluated as a unit in a clinical study (Friedman et
al 1991), contributing one unit recorded as persistent disease.
• In contrast, if the roots were evaluated independently, the tooth would
contribute two units: one healed and the other having persistent disease.
Tooth location and number of roots
Q6:Why are the reported
outcomes diverse?
63. Initial treatment or retreatment
Re-treatment 1 year
Root end filling 1 year Courtesy of Dr Steven Cohen, Toronto, Canada
Q6:Why are the reported
outcomes diverse?
64. Treatment providers
Providers of treatment in the different
studies varied from oral and maxillofacial
surgeons to endodontists, and from
resident students to qualified specialists,
with the reported outcomes varying
accordingly.
Q6:Why are the reported
outcomes diverse?
65. Outcome of predominantly assessed by radiographs
limitations of radiographs:
Radiographs are poorly standardized, Subjected to changes in
angulation and contrast.
Different observers may not agree with what they see on a radiograph, and
the same observer may disagree with himself or herself if asked to reassess
the same radiograph later.
Interpretation of radiographs is subject to bias.
These limitations of radiographs may undermine the reliability of the results.
• To minimize bias and inconsistency, assessment by blinded
examiners who are calibrated for standardized interpretation is
essential.
• This requirement has not been fulfilled in the majority of studies,
and thus the reported outcomes are likely to reflect differences in
radiographic interpretations.
Interpretation of radiographs
Q6:Why are the reported
outcomes diverse?
66. Follow-up period
• Healing after apical surgery is a dynamic process, requiring sufficient time
for completion.
• There has been some debate about the appropriate follow-up period to
demonstrate success. Some studies have reported significant lesion
reduction within 1 year but have required as much as 3 years for full
resolution.
• Kvist & Reit in a study reported 45 teeth that were healed at the 1-year
follow-up, however recurrence of disease in four teeth (9%) at the 4-year
follow-up.
Thus, short-term studies may not reflect the true, long-term outcome of apical
surgery .
Because studies vary considerably in the extent of follow-up periods, their
reported outcomes are likely to reflect this variability
Q6:Why are the reported
outcomes diverse?
67. Extent of the follow-up period : outcome classification
as ‘healing’ vs. ‘healed’.
-large excess of
sealer
-persistent apical
periodontitis
root-end
filling with
MTA
3 months
lesion is not
reduced.
After 6 months 1 year and 8 months
The lesion is replaced with new bone;
at the longer-term end-point.
the outcome is assessed as ‘healed.’Ørstavik D, Pitt Ford TR, eds.
Essential Endodontology: Prevention and Treatment of
Apical Periodontitis. Oxford: Blackwell Science, 1998.
Q6:Why are the reported
outcomes diverse?
68. Coronal restoration
The majority of studies do not provide detailed
information about the restorative status of the
treated teeth.
It is likely that in many studies the reported outcomes are
adversely influenced by inclusion of teeth with defective or
missing restorations.
Q6:Why are the reported
outcomes diverse?
69. Recall rate
• When subjects included in a study are not available for follow-up, their treatment outcome
is unknown.
• The results may be considered invalid, unless the unavailable subjects are deceased or
cannot be reached, suggesting that their absence is not related to the outcome.
• For this reason, a recall rate of at least 80% is required for a high level of evidence.
• The recall rates in the different studies vary from 18% to over 90%, while in many of
them studies the recall rate is not even reported .
This may be one of the reasons for the inconsistent outcomes reported among all the
studies.
For example, with a recall rate of 85%, Wang et al. report
that 74% of the teeth have healed.
According to their calculation, in the best-case scenario
80% of the teeth would be healed, while in the worst case
scenario 57% would be healed.
Q6:Why are the reported
outcomes diverse?
70. The key to achieving a favorable outcome after endodontic
treatment is related to controlling infection of the root canal
system (i.e. eliminating infection, and preventing
reinfection). Clinicians should be striving to achieve higher
treatment outcomes by taking a biological approach to
endodontic treatment and not simply concentrating on
achieving a radiopaque line in root canal.
Conclusion
71. -Three main prognostic factors influence the outcome of root canal
treatment and retreatment, the preoperative status of the periapical tissue,
the quality of the root canal filling And the quality of the coronal restoration
Summary points
-Endodontically treated teeth should be reviewed to assess outcome-
conventionally, this is done at least one year after the completion of endodontic
treatment.
-The outcome of endodontic treatment may be deemed to be favorable, uncertain, or
unfavourable, it is advisable to avoid using the terms “Success” and “Failure”.
-The probability of achieving a favorable outcome following endodontic
treatment. i.e. the tooth is symptom- free and functional and the associated
tissue appear clinically and radiographically healthy, can be over 95 percent.
Success and failure:
and one person may define success/failure completely differently from another person
There are several ways to measure and categorize the outcome of endodontic treatment. These can be broadly categorized into:
It’s useful in comparing the outcome of endodontic treatment and dental implant treatment.
The outcome of endodontic treatment is more likely to be favorable in:
-teeth with vital pulps
- teeth with inflamed pulps(e.g. irreversible pulpitis)
-Teeth with necrotic uninfected pulps.
Radiographically: these teeth would not have signs of preoperative periapical radiolucency. The probability of achieving a favorable outcome (i.e. maintaining a healthy periapical status) after endodontic treatment is in the region of )95 percent.
In teeth with signs of periapical periodontitis (i.e. periapical radiolucency on radiography) the probability of achieving a favorable outcome (i.e. curing an existing periapical periodontitis) after endodontic treatment is in the region of 85 percent. This is likely to be due to teeth affected by periapical periodontitis having a more established infection in the root canal system when compared to teeth unaffected by periapical periodontitis.
The literature has conflicting conclusions on the influence of the size of the preoperative periapical lesion on outcome of treatment. The likelihood of a favorable outcome appears to be higher when the size of the preoperative periapical lesion is small (<5mm).
Assessment of radiographic images has been shown to be highly inconsistent. The consistency of assessment can be significantly improved when structured observer and calibration strategies are applied, as suggested for endodontic treatment. However, the suggested strategies have not been frequently applied in endodontic outcome studies,
Teeth with clinical features that could adversely affect the prognosis, such as deep periodontal defects, have been excluded in several studies while specific studies include only teeth with poor prognosis, for example those affected by loss of the buccal bone plate.
(A) A mandibular second premolar with dens evaginatus, immature root formation, and apical periodontitis, after combined orthograde and surgical treatment and root filling with glass-ionomer cement.
(B) Clinical view showing a total loss of the buccal bone plate, suggesting a poor probability of healing.
A) A root-filled mandibular first molar with persistent apical periodontitis. The mesial lesion is considerably larger than the distal one.
(B) Completed surgery, including root-end filling with amalgam and varnish.
(C) After 2.5 years, the distal radiolucency is resolved, but the mesial one is not. The presence of symptoms suggests persistence of apical periodontitis.
(A) A root-filled
mandibular first molar with persistent apical periodontitis affecting the mesial root. (B) Completed orthograde
retreatment of the mesial canals. (C) After 1 year, the expanded lesion indicates persistence of apical periodontitis. As the
previous retreatment may have eliminated intra-canal bacteria, the infection may be sustained by extra-radicular bacteria.
(D) Completed surgery, including root-end filling with Super-EBA. (E) One year after surgery, the lesion is healed.
(Apical surgery and follow-up courtesy of Dr Steven Cohen, Toronto, Canada.)
Several evaluators, ideally including a radiologist, should be assigned to evaluate radiographs.
(A) A root-filled maxillary canine with a large excess of sealer and persistent apical periodontitis. (B) Completed surgery, including root-end filling with MTA. (C) After 3 months, some bone deposition is suggested but the lesion is not reduced. (D) After 6 months, there is little further improvement; if assessed at this and the previous end-points, the outcome would be recorded as ‘healing,’(E) After 1 year and 8 months, the lesion is replaced with new bone; at this longer-term end-point, the outcome is assessed as ‘healed.’