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Clinical-radiographic follow-up studies of
endodontic treatment: expectations and limitations
We all strive for
excellence, but
how well do we do?
Clinical-radiographic follow-up studies of
endodontic treatment: expectations and limitations
We all strive for
excellence, but
how well do we do?
How can we
monitor
improvement?
Clinical-radiographic follow-up studies of
endodontic treatment: expectations and limitations
We all strive for
excellence, but
how well do we do?
How can we
monitor
improvement?
Where do we seek
information to
support/adjust
treatment?
Clinical-radiographic follow-up studies of
endodontic treatment: expectations and limitations
•
Design of follow-up studies:
–
•
Critical issues in endodontic clinical research:
–
•
Tooth survival, case selection, criteria and harmonization - examples
The fundamental difference between prevention and treatment
–
•
RCTs, cohort studies, case controls, case series, retro- and prospective,
When will we ever learn?
Can we cure chronic apical periodontitis?
–
Histology, experiments, Ricucci, Brynolf, Wu & Wesselink
•
A change in concept from qualitative to quantitative microbial control
•
The futility of personal experience
–
•
A journey through a hypothetical practice situation
Precision in design
–
Stiches in embroidery
1
Design of follow-up studies
What do we know?
• Technical performance
– Length is important in cases of AP
– Width is controversial at best(worst), of no
consequence at worst (best)
– Cultivable bacteria left in the canal at the time of filling
are associated with outcome, measured in teeth with
AP mainly
• Biological and clinical factors
– tbd
Clinical-radiographic follow-up studies of
endodontic treatment: expectations and limitations
• Design of follow-up studies:
– RCTs (prosp)
– Cohort studies (r&p)
– Case controls (r&p)
• {Matched pairs}
– Case series (r&p)
– Case collection (r&p)
– Retro- and prospective – drop-outs!
Cumulative PAI Scores
AH
0
1
2
KP
3
4
0
1
2
PS
3
4
0
TIME: 0 to 4 years
1
2
3
4
Ørstavik et al., 1986
The single case report:
A valuable contribution to the scientific literature
Gould 3xO September 2001 editorial
• ”I wish to advocate for the validity and
value of the single case report. I believe
that the case report with appropriate
content remains an important contribution
to the body of clinical and diagnostic
information for oral health care providers
and researchers.”
2
Critical issues in endodontic
clinical research
Different situations of radiographic follow-up methods
• Case-by-case monitoring for healing or emergence of apical
periodontitis: everyday practice, quality assurance
• Particular clinical situations: eg, perforations,
apexification,cyst size reduction: practice and case reports –
very difficult to produce high-quality data
• Feasibility studies: case series: New materials
• Scientific clinical studies: influence of specific
clinical/biological/technical variables; need a homogenous
baseline
Clinical Studies: Final and
Surrogate Endpoints
• Clinical outcome
– Disease:
• Local: presence of AP
• disseminated
– Pain
• During treatment
• epidemiology
– Retention of
teeth/restorations
• Biological outcome
– Microbiological status of
tissues
• much done, more
attention?
– Tissue status
• Healing of lesion
• Nerves, vessels, cells
• Biological markers
• Technical outcome
– Time spent
– Operator’s experience
Tooth retention
Parameter
Odds Ratio
95 CI
Number of proximal contacts (two=O, zero or one=l)
2,7
1,4-5,1
Age (continuous, from 50 years, per 10-year increase)
1,4
1,1-1,9
History of facial injury (no=O, yes=l)
3,6
1,2-10,5
Number of missing nonwisdom teeth
1,5
1,0-2,1
Plaque (none or light=0, moderate=l, heavy=2)
1,7
1,0-2,6
Caplan DJ, Weintraub JA. Factors related to loss of root canal filled
teeth. J Public Health Dent. 1997 Winter;57(1):31-9.
Factors related to loss of root canal filled teeth.
Caplan DJ, Weintraub JA. J Public Health Dent. 1997 Winter;57(1):31-9.
• The results suggest that variables at the tooth level
(number of proximal contacts), mouth level (number of
missing teeth, plaque), and patient level (age, history of
facial injury) are associated with loss of RCF teeth,
implying that loss of a particular tooth is influenced by
more than tooth-specific features. The findings also
suggest that variables ascertainable at the time of
treatment planning are related more strongly to
subsequent loss of an RCF tooth than are endodontic or
postobturation restorative factors.
Tooth survival: Endo-Perio
Per cent teeth retained
100
80
60
40
20
0
Periodontal Practices Today. 2008;5:15 - 20
Survival of endodontically treated teeth with severe periodontal involvement
Saetervold, Heidi / Bruseth, Ane Marthe / Orstavik, Dag / Preus, Hans R
Tooth survival: Endo-Perio
Per cent teeth retained
100
80
60
40
20
0
Tooth
survival is of interest when several end diagnoses are possible,
Periodontal Practices Today. 2008;5:15 - 20
eg,
perio,ofcaries,
restorative
considerations,
addition involvement
to endodontic.
Survival
endodontically
treated
teeth with severein
periodontal
Saetervold,
/ Bruseth,
Marthe
/ Orstavik,
/ Preus,
Here, the
control Heidi
group
has aAne
100%
survival,
butDag
that
doesHans
notRmean it has no AP.
Community Dent Oral Epidemiol. 2003 Feb;31(1):59-67
Risk indicators for apical periodontitis
Lise-Lotte Kirkevang and Ann Wenzel
Variables
Category
Age
20-29 (n = 111)
1.00
-
30-39 (n = 153)
1.82
0.80-4.12 (0.15)
40-49 (n = 169)
1.24
0.54-2.86 (0.61)
50-59 (n = 144)
2.38
0.97-5.85 (0.59)
60+ (n = 36)
1.80
0.40-8.39 (0.43)
No (n = 325)
1.00
-
Yes (n = 250)
1.64
1.00-2.84 (0.05)
0 (n = 82)
3.98
1.87-8.46 (0.00)
1-5 (n = 309)
1.00
-
6-9 (n = 127)
0.89
0.47-1.67 (0.70)
10-19 (n = 56)
0.99
0.39-2.47 (0.90)
20+ (n = 12)
12.63
0.79-200.07 (0.07)
Smoking
Number of
services from
the dentist
Adjusted OR
95% CI (P)
Adjusted odds ratio (OR) with 95% confidence intervals (CI) and P-values.
Variables
Category
Number of teeth
1-18 (n = 22)
1.00
-
19-27 (n = 280)
0.66
0.18-2.49 (0.54)
28 (n = 311)
0.34
0.09-1.34 (0.12)
0 (n = 403)
1.00
-
1 (n = 141)
0.95
0.51-1.79 (0.88)
2 (n = 69)
2.63
1.01-6.87 (0.05)
Number of inadequate
coronal fillings
0-2 (n = 474)
1.00
-
3 (n = 134)
2.44
1.17-5.07 (0.02)
Number of root fillings
0 (n = 295)
1.00
-
1 (n = 140)
11.18
5.99-20.85 (0.00)
2 (n = 178)
80.07
38.19-167.87 (0.00)
Number of secondary
caries
Adjusted OR
95% CI (P)
Adjusted odds ratio (OR) with 95% confidence intervals (CI) and P-values.
Individuals with AP, %
100
Adapted from: Harald Eriksen 2008
in: Ørstavik & Pitt Ford, Essential
Endodontology
80
l
60
40
d e
c
a b
f g h
i j
n
r s
o p q
k
20
0
The prevalence of apical periodontitis in different populations.
a, Dugas et al 2003; b, Marques et al 1998; c, Frisk & Hakeberg 2005; d, Loftus et al 2005; e, Buckley & Spangberg 1995;
f, DeCleen et al 1993; g, Eriksen et al 1991; h, Dugas et al 2003; i, Kirkevang et al 1991; j, Frisk & Hakeberg 2005; k, Chen
et al 2007; l, Jiménez-Pinzón et al 2004; n, De Moor et al 2000; o, Saunders et al 1997; p, Sidaravicius et al 1999; q,
Tsuneishi et al 2005; r, Kabak & Abbott 2005; s, Segura-Egea et al 2005.
100
Individuals with AP, %
Segura-Egea JJ, Jiménez-Pinzón A, Ríos-Santos JV, Velasco-Ortega E,
Cisneros-Cabello R, Poyato-Ferrera M. Int Endod J. 2005 Aug;38(8):564-9.
r s
High prevalence of apical80
periodontitis amongst type 2
diabetic patients. Department of Stomatology, School of Dentistry,
University of Seville, Seville, Spain.
60
RESULTS: Apical periodontitis
in at least one tooth was
found in 81.3% of diabetic patients and in 58% of controlk
subjects (P = 0.040; OR = 3.2; 95% CI = 1.1-9.4). Amongst diabetic j
l
n
o p q
40whereas in the control subjects 4% of teeth
patients 7% of the teeth had AP,
were affected (P = 0.007; OR = 1.8; 95% CI = 1.2-2.8). CONCLUSIONS:
Type 2 diabetes mellitus is significantly associated with an increased
prevalence of AP.
20
0
Fig. 6. The prevalence of apical periodontitis in different populations.
a, Dugas et al 2003; b, Marques et al 1998; c, Frisk & Hakeberg 2005; d, Loftus et al 2005; e, Buckley &
Spangberg 1995; f, DeCleen et al 1993; g, Eriksen et al 1991; h, Dugas et al 2003; i, Kirkevang et al 1991; j, Frisk
& Hakeberg 2005; k, Chen et al 2007; l, Jiménez-Pinzón et al 2004; n, De Moor et al 2000; o, Saunders et al 1997;
p, Sidaravicius et al 1999; q, Tsuneishi et al 2005; r, Kabak & Abbott 2005; s, Segura-Egea et al 2005.
Endodontics is:
Prevention or treatment of
apical periodontitis
which in practice means
Protection against or
elimination(?) of root
canal infection
Diagnostics, choice of
treatment method, irrigation,
medication and root filling are
all means towards this end
Ørstavik 1988
Endodontics is:
Prevention or treatment of
apical periodontitis
which in practice means
Protection against or
elimination(?) of root
canal infection
How to monitor this disease?
Ørstavik 1988
• success when
– a, the contours, width and structure of the
periodontal margin were normal
– b, the periodontal contours were widened
mainly around the excess filling
• failure when there was
– a) a decrease in the periradicular rarefaction
– b) an unchanged periradicular rarefaction
– c) an appearance of new rarefaction or an
increase in the initial
• uncertain when
– a) there were ambiguous or technically
unsatisfactory control radiographs which
could not for some reason be repeated
– b) the tooth was extracted prior to the 3-year
follow-up owing to the unsuccessful
treatment of another root of the tooth
Success/failure criteria
(Strindberg 1956)
Probability assessments
• Definitively no disease
1
• Probably no disease
2
• Uncertain
3
• Probably disease
4
• Definitively disease
5
An attempt to systematize the ”clinical assessment situation”
Scoring Systems in Clinical
Dentistry
• Caries: limited progress until DMF index was
established (1938)
• Gingivitis & marginal periodontitis:
confusion until indices were applied
(1950-60)
• Apical periodontitis: Calibrated indices? Xray digitized measurements? Quantification
by (CB)CT?
The PAI Scoring System
• Apical periodontitis: A calibrated index
Ørstavik et al. 1986: The periapical index: a scoring system for
tradiographic assessment of apical periodontitis
300 teeth with histology and radiographs.
(Note in passing: very few – 7% - without
some inflammatory reactions)
Brynolf 1967: A histological and
radiological study of the periapical
region of human upper central
incisors
Brynolf 1967:
A histological and radiological
study of the periapical region of
human upper central incisors
Ørstavik et al. 1986:
The periapical index: a scoring
system for tradiographic
assessment of apical periodontitis
Seven histologic/radiographic
groups
Five radiographic categories on an
ordinal scale of severity
*The PAI scoring system is a radiographic
interpretation on a 5 point scale from 1-5 in
order of absence to presence and increasing
severity of disease.
*It uses a reference set of radiographs with
corresponding line drawings and their
associated score on a photographic print or
computer screen.
*The scores are based on a correlation with
inflammatory periapical status confirmed by
histology.
Nine radiographs from Brynolf’s selection
were taken as representatives of the five
categories, unwillingly verbally described as:
1 - Normal apical periodontium
2 – Structural changes in periapical bone
3 – Structural changes with mineral loss
4 – Overt radiolucency
5 – Structural changes peripheral to radiolucency
• Find the reference
radiograph where the
periapical area most
closely resembles the
periapical area you
are studying. Assign
the corresponding
score to the observed
root.
• When in doubt,
assign a higher
score.
• For multirooted teeth,
use the highest of the
scores given to the
individual roots.
• All teeth must be
given a score.
Calibration
• Material:
• Reference scale
• Set of written instructions for scoring
• Set of 100 radiographs, one tooth in each is scored. The
’true scores’ have been determined by consensus of two
endodontists involved with the development of the
system.
• Excel file for computation of essential statistical
parameters.
• 20 calibrated scorers world wide – kappa values from
0.62 to 0.80
Usage
• 16 countries, 50+ publications
• Retrospective clinical follow-ups
• Epidemiological studies
• Prospective and experimentalstudies
The ridit statistic
Parametric statistics
Periapical
improvement
with time
PAI 3-5 at start
4.5
4
Trope et al 1999
3.5
C
O
3
2.5
2
0
4
12
26
52
TIME, weeks
PAI difference over time:
Parametric statistics
Change of PAI in cases with bacteria absent or present at the second
appointment. Single visit cases are not included.
From: Waltimo et al: J Endod, Volume 31(12).December 2005.863-866
Post Placement
70
60
50
40
Filling
30
Crown
Post
20
10
0
1
2
3
PA I sco r e at co nt r o l
4
Individuals with AP, %
100
Adapted from: Harald Eriksen 2008
in: Ørstavik & Pitt Ford, Essential
Endodontology
80
l
60
40
d e
c
a b
f g h
i j
n
r s
o p q
k
20
0
The prevalence of apical periodontitis in different populations.
a, Dugas et al 2003; b, Marques et al 1998; c, Frisk & Hakeberg 2005; d, Loftus et al 2005; e, Buckley & Spangberg 1995;
f, DeCleen et al 1993; g, Eriksen et al 1991; h, Dugas et al 2003; i, Kirkevang et al 1991; j, Frisk & Hakeberg 2005; k, Chen
et al 2007; l, Jiménez-Pinzón et al 2004; n, De Moor et al 2000; o, Saunders et al 1997; p, Sidaravicius et al 1999; q,
Tsuneishi et al 2005; r, Kabak & Abbott 2005; s, Segura-Egea et al 2005.
Weaknesses of the PAI system
• Front tooth reference only
• Moderate specifity
Cone beam CT
The potential
applications of cone
beam computed
tomography in the
management of
endodontic
problems
Patel & al.
2007
Increased
sensitivity = better
disease detection
Periapical
radiographs are still
current best or
adequate practice
3
The fundamental difference
between prevention and
treatment
Prognosis for Pulpectomy:
Prevention of Apical Periodontitis
•
•
•
•
•
Strindberg 1956
Kerekes & Tronstad 1979
Ørstavik et al 1986(2004)
Sjögren et al 1990
Marquis et al 2006
94
97
94
97
93
• This is probably a reflection of an almost
complete success – failures are iatrogenic,
via contamination, and avoidable
Prognosis for Root Canal Infection:
Treatment of Apical Periodontitis
•
•
•
•
•
•
Strindberg 1956
Kerekes & Tronstad 1979
Ørstavik et al 1986(2004)
Sjögren et al 1990
Marquis et al 2006
Zmener & Pamejer 2004
88
91
79
86
80
89
• This is probably a reflection of persistent infection
– failures are due to inadequate disinfection
(+ the contaminants from the previous slide)
Individuals with AP, %
100
Adapted from: Harald Eriksen 2008
in: Ørstavik & Pitt Ford, Essential
Endodontology
80
l
60
40
d e
c
a b
f g h
i j
n
r s
o p q
k
20
0
The prevalence of apical periodontitis in different populations.
a, Dugas et al 2003; b, Marques et al 1998; c, Frisk & Hakeberg 2005; d, Loftus et al 2005; e, Buckley & Spangberg 1995;
f, DeCleen et al 1993; g, Eriksen et al 1991; h, Dugas et al 2003; i, Kirkevang et al 1991; j, Frisk & Hakeberg 2005; k, Chen
et al 2007; l, Jiménez-Pinzón et al 2004; n, De Moor et al 2000; o, Saunders et al 1997; p, Sidaravicius et al 1999; q,
Tsuneishi et al 2005; r, Kabak & Abbott 2005; s, Segura-Egea et al 2005.
Results of endodontic treatment based on the
presence of apical periodontitis associated with
root-filled teeth evaluated from radiographs.
•
•
•
•
•
•
•
•
•
•
•
Reference
Avg age
Eriksen and Bjertness 1991 (Norway)
50
Ödesjö et al. 1990 (Sweden)
45
Imfeld 1991 (Switzerland)
66
de Cleen et al. 1993 (the Netherlands)
38
Buckley and Spångberg 1995 (USA)
45
Ray and Trope 1995 (USA)
Saunders et al. 1997 (Scotland)
(20-60+)
Weiger et al. 1997 (Germany)
Marques MD et al. 1998 (Portugal)
35
Georgopoulou MK et al. 2005 (Greece)
48
• Mean value
• ”Success range”:
45
Succ
64
75
69
61
69
61
42
39
78
40
Fail
36
25
31
39
31
39
58
61
22
60
63
37
39-78 %
From: Harald Eriksen 2008 In: Ørstavik & Pitt Ford, Essential Endodontology
Results of endodontic treatment based on the
presence of apical periodontitis associated with
root-filled teeth evaluated from radiographs.
•
•
•
•
•
•
•
•
•
•
•
Reference
Avg age
Eriksen and Bjertness 1991 (Norway)
50
Ödesjö et al. 1990 (Sweden)
45
Imfeld 1991 (Switzerland)
66
de Cleen et al. 1993 (the Netherlands)
38
Buckley and Spångberg 1995 (USA)
45
Ray and Trope 1995 (USA)
Saunders et al. 1997 (Scotland)
(20-60+)
Weiger et al. 1997 (Germany)
Marques MD et al. 1998 (Portugal)
35
Georgopoulou MK et al. 2005 (Greece)
48
• Mean value
• ”Success range”:
45
Succ
64
75
69
61
69
61
42
39
78
40
Fail
36
25
31
39
31
39
58
61
22
60
63
37
39-78 %
From: Harald Eriksen 2008 In: Ørstavik & Pitt Ford, Essential Endodontology
Factors known to affect the
prognosis of ”endodontic treatment”
• Cotton TP, Schindler WG, Schwartz SA, Watson WR, Hargreaves
KM.
A retrospective study comparing clinical
outcomes after obturation with
Resilon/Epiphany or Gutta-Percha/Kerr
sealer.
(endodontist, recalled at 2–25 months)
J Endod. 2008 Jul;34(7):789-97. Epub 2008 May 12.
Factors known to affect the
prognosis of ”endodontic treatment”
•
A retrospective study comparing clinical
outcomes after obturation with Resilon/Epiphany or Gutta-Percha/Kerr sealer. J Endod.
Cotton TP, Schindler WG, Schwartz SA, Watson WR, Hargreaves KM.
2008 Jul;34(7):789-97. Epub 2008 May 12.
Healed
Nonhealed
Total
Obturation material, n (%)
p Value
1
Resilon
42 (79.2)
11 (20.8)
43 (100)
Gutta-percha
39 (78.0)
11 (22.0)
50 (100)
Total (some w no pulp Dx)
81
22
103
Factors known to affect the
prognosis of ”endodontic treatment”
•
A retrospective study comparing clinical
outcomes after obturation with Resilon/Epiphany or Gutta-Percha/Kerr sealer. J Endod.
Cotton TP, Schindler WG, Schwartz SA, Watson WR, Hargreaves KM.
2008 Jul;34(7):789-97. Epub 2008 May 12.
Healed
Nonhealed
Total
Preoperative lesion, n
(%)
p Value
<.001
Yes
43 (66.2)
22 (33.8)
65 (100)
No
38 (100)
0 (0.0)
38 (100)
Total
81
22
103
Factors known to affect the
prognosis of ”endodontic treatment”
• Gender
.06 Males worse
• Appointments
.06 Multiple worse
• Pulp diagnosis
.001 Nonvital worse
• Preoperative lesion
.003 Present worse
• No. of canals obturated
1
• Recall time
.68
• Age
.25
• Tooth position
.26
• Obturation material
1
Conclusion:
Pulpectomy is apples,
apical periodontitis is oranges,
and clinic, biology, research, and
treatment practices should be
considered separately for the two
4
Can we cure chronic apical
periodontitis?
Oral Surg Oral Med Oral Pathol Oral Radiol
Endod. 2009 Oct;108(4):609-21. Epub 2009 Aug
28.
Wound healing of apical tissues after root
canal therapy: a long-term clinical,
radiographic, and histopathologic observation
study.
Ricucci D, Lin LM, Spångberg LS
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Oct;108(4):609-21. Epub
2009 Aug 28.
Wound healing of apical tissues after root canal therapy: a long-term clinical,
radiographic, and histopathologic observation study.
Ricucci D, Lin LM, Spångberg LS
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Oct;108(4):609-21. Epub
2009 Aug 28.
Wound healing of apical tissues after root canal therapy: a long-term clinical,
radiographic, and histopathologic observation study.
Ricucci D, Lin LM, Spångberg LS
J Endod. 2009 Apr;35(4):493-502.
Histologic investigation of root canal-treated
teeth with apical periodontitis: a retrospective
study from twenty-four patients.
Ricucci D, Siqueira JF Jr, Bate AL, Pitt Ford TR.
This study intended to examine histologically root canal-treated teeth
evincing apical periodontitis lesions and correlate the findings with
clinical observations. Specimens were obtained from 24 patients (12
asymptomatic and 12 symptomatic) by extraction or endodontic
surgery and consisted of roots or root tips and the associated
pathologic lesion. Specimens were processed for histologic analysis,
and serial sections were evaluated. Findings were correlated with
clinical observations according to the presence or absence of
symptoms. The mean period elapsed from treatment to specimen
retrieval in the asymptomatic group was 7.5 years, as compared with
2.2 years in the symptomatic group.
J Endod. 2009 Apr;35(4):493-502.
Histologic investigation of root canal-treated
teeth with apical periodontitis: a retrospective
study from twenty-four patients.
Ricucci D, Siqueira JF Jr, Bate AL, Pitt Ford TR.
All specimens exhibited periradicular inflammation. Bacteria were
visualized in all cases, except for 1 specimen from the
asymptomatic group in which a foreign body reaction to overfilled
material was the probable reason for emergent disease in a
previously vital case. Irrespective of the presence of symptoms,
bacteria were always located within the root canal system, although
they were also observed in the periradicular tissues in 1
asymptomatic and 4 symptomatic teeth. In general, intraradicular
bacterial colonization was heavier in symptomatic failed teeth. The
present findings support the role of intraradicular infections, usually in
the form of biofilms, as the primary cause of endodontic treatment
failure.
J Endod. 2009 Apr;35(4):493-502.
Histologic investigation of root canal-treated teeth with apical
periodontitis: a retrospective study from twenty-four patients.
Ricucci D, Siqueira JF Jr, Bate AL, Pitt Ford TR.
Figure 2. …(B) Three-year follow-up
radiograph showing a conspicuous reduction
in size of the lesion, but a residual
radiolucency was evident. Tooth was
symptom-free. (C) Patient presented 10 years
after completion of treatment, with loss of the
coronal restoration. Clinical inspection
revealed recurrent caries. A radiograph
demonstrated that the apical radiolucency had
remained the same size. Although the tooth
was still apparently restorable, the patient
opted for extraction. (Taylor's modified Brown
& Brenn, original magnification ×100 and
×400).
J Endod. 2009 Apr;35(4):493-502.
Histologic investigation of root canal-treated teeth with apical
periodontitis: a retrospective study from twenty-four patients.
Ricucci D, Siqueira JF Jr, Bate AL, Pitt Ford TR.
Figure 2. …(B) Three-year follow-up
radiograph showing a conspicuous reduction
in size of the lesion, but a residual
radiolucency was evident. Tooth was
symptom-free. (C) Patient presented 10 years
after completion of treatment, with loss of the
coronal restoration. Clinical inspection
revealed recurrent caries. A radiograph
demonstrated that the apical radiolucency had
remained the same size. Although the tooth
was still apparently restorable, the patient
opted for extraction. (D) Section passing
through an oblique foramen, short of the apex.
The lesion had remained attached to the apex
(Taylor's modified Brown & Brenn, original
magnification ×25). (E, F) Magnifications of the
foramen area show large bacterial
aggregations present intermixed with filling
material and faced against a severe
concentration of PMN leukocytes (Taylor's
modified Brown & Brenn, original
magnification ×100 and ×400).
J Endod. 2009 Jul;35(7):1009-12.
Accuracy of periapical radiography and cone-beam computed
tomography scans in diagnosing apical periodontitis using
histopathological findings as a gold standard.
de Paula-Silva FW, Wu MK, Leonardo MR, da Silva LA, Wesselink PR.
The periapex of 83 treated or
untreated roots of dogs' teeth was
examined using periapical
radiography (PR), cone-beam
computed tomography (CBCT)
scans, and histology. Sensitivity,
specificity, predictive values, and
accuracy of PR and CBCT
diagnosis were calculated.
J Endod. 2009 Jul;35(7):1009-12.
Accuracy of periapical radiography and cone-beam computed
tomography scans in diagnosing apical periodontitis using
histopathological findings as a gold standard.
de Paula-Silva FW, Wu MK, Leonardo MR, da Silva LA, Wesselink PR.
In group 1, root canal treatment was performed in
healthy teeth. Root canals in groups 2 through 4 were
infected until AP was confirmed by PR. Roots with AP
were treated by one-visit therapy in group 2, by two-visit
therapy in group 3, and left untreated in group 4. The
radiolucent area in PRs and the volume of CBCTscanned periapical lesions were measured before and
6 months after treatment.
Figure 1. Three representative microscopic
fields around the root apex in three orientations:
the longitudinal axis through the center of the
apical opening and at 45° to this long axis at
each side. The number of inflammatory cells
was counted in each microscopic field using a
counting frame.
J Endod. 2009 Jul;35(7):1009-12.
Accuracy of periapical radiography and cone-beam computed
tomography scans in diagnosing apical periodontitis using
histopathological findings as a gold standard.
de Paula-Silva FW, Wu MK, Leonardo MR, da Silva LA, Wesselink PR.
Figure 2. A specimen in group 3
showing a small periapical lesion
(magnification 10×) measured as 1.2
mm2 in PR and 2.8 mm3 in a CBCT
scan. Inflammatory cells were
restricted to the apical foramina
surrounding extruded material
particles.
J Endod. 2009 Jul;35(7):1009-12.
Accuracy of periapical radiography and cone-beam computed
tomography scans in diagnosing apical periodontitis using
histopathological findings as a gold standard.
de Paula-Silva FW, Wu MK, Leonardo MR, da Silva LA, Wesselink PR.
In group 1, root canal treatment was
performed in healthy teeth. Root canals in
groups 2 through 4 were infected until AP
was confirmed by PR. Roots with AP were
treated by one-visit therapy in group 2, by
two-visit therapy in group 3, and left
untreated in group 4. The radiolucent area
in PRs and the volume of CBCT-scanned
periapical lesions were measured before
and 6 months after treatment.
Int Endod J. 2003 Nov;36(11):787-802.
Bacterial status in root-filled teeth exposed to the oral environment by
loss of restoration and fracture or caries--a histobacteriological study of
treated cases.
Ricucci D, Bergenholtz G.
AIM: To describe histological and microbiological findings in teeth where
root fillings had been exposed to caries and the oral environment for a
prolonged period. METHODOLOGY: For inclusion in the study, only teeth
with a follow-up period of 3 years or more and those that had been
without proper restoration for at least a period of 3 months were
considered. Some root fillings had been without restoration for several
years. In all, 39 roots representing 32 teeth were examined by histology.
Int Endod J. 2003 Nov;36(11):787-802.
Bacterial status in root-filled teeth exposed to the oral environment by
loss of restoration and fracture or caries--a histobacteriological study of
treated cases.
Ricucci D, Bergenholtz G.
RESULTS: The majority of the specimens were without a discernible
periapical bone lesion as assessed by radiography. Osteolytic lesions
were seen with five roots. Longitudinal tissue sections stained with a
modified Brown/Brenn staining technique revealed presence of stainable
bacteria in abundance at the canal entrance and in dentinal tubules but
were absent mid-root and apically in all but two specimens. Soft tissue
attached to the root tip and in apical ramifications displayed distinct
inflammatory cell infiltrates, suggesting microbial exposure in 7 of the 39
roots examined. In all other specimens, inflammatory cell infiltrates were
either nonexistent or sparse and then associated with extruded sealer
material. CONCLUSIONS: Well-prepared and filled root canals resist
bacterial penetration even upon frank and long-standing oral exposure by
caries, fracture or loss of restoration.
Int Endod J. 2003 Nov;36(11):787-802.
Bacterial status in root-filled teeth exposed to the oral environment by
loss of restoration and fracture or caries--a histobacteriological study of
treated cases.
Ricucci D, Bergenholtz G.
Figure 1 Specimen (tooth 25) of a 29-year-old man. The tooth
had been treated for a vital pulp condition in one visit and
restored with resin composite. One and a half years later the
patient presented with a deep fracture of the palatal cusp and
received a provisional restoration. The patient never returned
for final treatment and was not seen until 3 years later when the
tooth presented with extensive caries, although some temporary
cement was still in place (A). The tooth was deemed
nonrestorable and was extracted. The radiograph in (A), taken
in conjunction with the extraction 4 years and 6 months post to
the initial endodontic treatment, shows a normal periapical bone
structure. Specimen after the extraction in (B) shows carious
tissue and dental plaque in contact with the root filling. After
demineralization, the apical third was separated, and the two
pieces were embedded separately (C, D). Histological
examination of the soft tissue in the apical portions of the
root demonstrated noninfiltrated connective tissue and
some hard tissue repair of previous resorptive defects (E–
G). Examining the specimen for stainable bacteria (H–K)
revealed bacterial plaque linings of the root-canal walls at the
entrance of the canal (H). Two insets demonstrate dentinal
tubules invaded by bacterial profiles of different morphology.
Apical to the area in (H), stainable bacteria were reduced and
were seen mixed with sealer material (black clumps; I). In an
area yet closer to the middle third of the root (J) and
apically to (K), no stainable bacteria were observed.
5
From qualitative to quantitative
microbial control
From Qualitative to Quantitative
Microbial Reduction
From Qualitative to Quantitative
Microbial Reduction
Qualitative Microbial Removal:
A Fallacy?
Perio
7
”On the road to damnation”
5
”On the road to salvation?”
Odds ratio
3
Caries
Pulp/AP
Pulp/AP
Perio
Caries
1
18-44 år
45+
Brennan DS, Spencer AJ, Szuster FS. Provision of extractions by main diagnoses. Int Dent J. 2001 Feb;51(1):1-6.
Australia: Practitioners completed service logs over one to two typical clinical days.
Bacteriology and the prognosis of
”endodontic treatment”
• …When no bacteria remained [in the root canal
before filling], healing occurred independently of the
quality of the root filling. In contrast, when bacteria
remained, there was a greater correlation with nonhealing in poor-quality root fillings than in technically
well-performed fillings. …..
• IE, we must maintain a high technical standard to
cover up for failure to disinfect the root canal
• How well do we do?
Fabricius L, Dahlén G, Sundqvist G, Happonen RP, Möller AJ. Influence of residual bacteria on periapical tissue
healing after chemomechanical treatment and root filling of experimentally infected monkey teeth. Eur J Oral Sci. 2006
Aug;114(4):278-85.
Results of endodontic treatment based on the
presence of apical periodontitis associated with
root-filled teeth evaluated from radiographs.
•
•
•
•
•
•
•
•
•
•
•
Reference
Avg age
Eriksen and Bjertness 1991 (Norway)
50
Ödesjö et al. 1990 (Sweden)
45
Imfeld 1991 (Switzerland)
66
de Cleen et al. 1993 (the Netherlands)
38
Buckley and Spångberg 1995 (USA)
45
Ray and Trope 1995 (USA)
Saunders et al. 1997 (Scotland)
(20-60+)
Weiger et al. 1997 (Germany)
Marques MD et al. 1998 (Portugal)
35
Georgopoulou MK et al. 2005 (Greece)
48
• Mean value
• ”Success range”:
45
Succ
64
75
69
61
69
61
42
39
78
40
Fail
36
25
31
39
31
39
58
61
22
60
63
37
39-78 %
From: Harald Eriksen 2008 In: Ørstavik & Pitt Ford, Essential Endodontology
The prognosis
• All teeth, the real world:
67%
• Follow-up of vital teeth with root filling 95%
• Follow-up of infected teeth treated
with root filling
85%
• Follow-up of conservative revision
70%
• 40/40/20 in your practice?
• How well do we do?
?%
The prognosis
• All teeth, the real world:
67%
• Follow-up of vital teeth with root filling
95%
• Follow-up of infected teeth treated
with root filling
85%
• Follow-up of conservative revision
70%
• 40/40/20 in your practice?
86%
• How well do we do?
Cotton TP et al. J Endod. 2008 Jul;34(7):789-97: (endodontist’s practice)
79%
Trope M et al. J Endod. 1999 May;25(5):345-50: (University Clinic, clinical study) 74%
What lies behind the finding that
every third root filled tooth has apical
periodontitis?
The incidence of healing after treatment of apical
periodontitis may be alarmingly low
Arguments suggesting bacterial
removal is difficult
• Tx results are worse with for AP than for
pulpectomy
• They are alarmingly low measured with PA
radiographs, and even much worse when CBCT is
applied
• Many more of the successsful vital cases
becomes infected and failing with CBCT
• Histology reveals microbes in (almost) every case
of teeth with inflammatory changes
• Inflammatory changes are abundant around root
filled teeth
6
The futility of personal experience:
the strongest argument for clinical
studies
Assessment of one’s own
cases
• Careful selection of cases for systematic studies:
– Preoperative diagnosis
AP/NAP
– Complications
– Technically difficult cases
– Surgical variables, if applicable
• Limitations of one’s own long-term follow-up experiences
Self-assessment: for practical
purposes, we have to og back to the
success/failure concept
• Suppose 200 patients are seen for control each year
(5 per week, 40 wks),
• this gives a 95% confidence interval for success rates
around 85% of
• 80 to 90%
• i.e., there is no way anyone can register a real
change in treatment outcome of less than some 10%!
• Before that, bias in case selection and uncontrollable
drop-outs are inevitable
Self-assessment: example
• You want to follow your own experiences with one-step
endodontics
• Let us suppose that of the 200 patients you get in for
recall, 80 had CAP,
• of which at least ¼ for various reasons had to be treated
in 2 or more appointments anyway, leaving 60,
• which gives a conf int of 76 to 94%
• i.e., there is no way anyone can register a real change
in therapeutic outcome of less than some 20% on a
yearly basis
’It works in my hands’:
How many cases does one really
need to document a difference in
performance? To pursuade a
colleague to change his ways?
Treatment categories (groups)
Outcome
Old method New method
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------Success
85
94
179 0,895
Failure
15
6
21 0,105
100
100
200
1
Success %
85
94
89,5
89,5
179
10,5
10,5
21
0,226257
0,226257
1,9285714 1,9285714
Chi-square value:
Degrees of freedom:
0,452514
3,8571429
4,3096568
1
0,05
0,01
3,84
6,63
Even 200 cases are not very
discriminating: How many cases are
followed systematically in any practice?
Moreover, controlling and randomizing
the variables influencing bacteria in the
canal, and other variables affecting the
final outcome are probably never done in
any practice – and it is no longer
considered ethical
Finally: any new method or new
material is correctly applied to simple
cases first, recognizing the learning
curve.
When such cases are retrospectively
assessed, they should have a better
outcome than the average or
complicated case
Conclusion: assessment of
one’s own cases
• There are serious limitations just by the numbers
needed, in one’s own ability to assess outcome
• Base-line harmonization is almost impossible
and
• Case selection is crucial
Conclusion: assessment of
one’s own cases
• There are serious limitations just by the numbers
needed, in one’s own ability to assess outcome
• Base-line harmonization is almost impossible
and
• Case selection is crucial
• But: the unusual case will always evade
systematic studies, and treatment will still
have to be based on hearsay and clinical
judgment: cf the plea for the case report
7
Precision in design
Examples by title
• 1950: 1000 Fälle von Gangränbehandlung nach der
Walkhoffschen Methode. (case series, pro-retro)
• 1985: A comparison of antimicrobial effects of calcium
hydroxide and iodine-potassium iodide. (cohort study,
retro)
• 2008: Clinical and radiographic comparison of primary
molars after formocresol and electrosurgical pulpotomy:
a randomized clinical trial.
• 2008: Periapical radiographs overestimate root canal
wall thickness during post space preparation.
(paraclinical, high precision)
Hypothesis testing
Epidemiological
True
Clinical
Probable
In vivo: animal
Likely
Ex vivo
Doable
In vitro
Possible
Laboratory
Technically possible
Literature
Basic or done before
Clinical studies: done at
chairside
• Diagnosis
– Xrays, pain
• Treatment
– Prophylaxis,
medicaments, materials,
techniques
• Disease
– Monitoring, criteria
• Tooth survival
Ex vivo
• Wikipedia: Ex vivo (Latin: out of
the living) means that which takes
place outside an organism. In
science, ex vivo refers to
experimentation or measurements
done in or on living tissue in an
artificial environment outside the
organism with the minimum
alteration of the natural conditions.
• Focus is on re-insertion into the
human body/complete organism
In vitro
• From Wikipedia, the free encyclopedia
• In vitro (Latin for within the glass)
refers to the technique of performing
a given experiment in a controlled
environment outside of a living
organism; for example in a test tube.
In vitro – ex vivo
•
From Wikipedia, the free encyclopedia
• In cell biology, ex vivo procedures often involve
living cells or tissues taken from an organism and
cultured in a laboratory apparatus, usually under
sterile conditions with no alterations for up to 24
hrs. Experiments lasting longer than this using
living cells or tissue are typically considered to be
in vitro. One widely performed ex vivo study is the
chick chorioallantoic membrane (CAM) assay. In
this assay, angiogenesis is promoted on the CAM
membrane of a chick embryo outside the organism
(chicken).
Technological experiments
• Physical testing:
– Materials, techniques
• Chemical testing:
– Composition, reactions
• Manipulative and functional tests:
– Bench-top usage tests: working
time, setting time, leakage (like ex
vivo, but the process is lab defined)
Animal experiments
• Biological tests
– Toxicity, allergenicity,
inflammatory potential
• Usage tests
– Medicaments and
devices applied as
suggested for human
use
Choosing the relevant test
Target
Physical & chemical properties
Clinical
Animal Lab&Cell Literature
+/-
+
+++
++++
-
+
+
++++
Biocompatibility
+/-
+++
+
++++
Debris removal
+
+
++++
++
++
+++
++++
+/-
Antibacterial
++++
+
++
++++
Disease
++++
++
-
+/-
Tooth survival
++++
-
++
+/-
Genotoxicity
Leakage
Root canal disinfection:
evidence-based practice
Law A, Messer H. Endod. 2004 Oct;30(10):689-94
100
75
Preoperative
Post irrigation
Post medication
50
25
25 % remain infected!!
0
S 91
Sh 00
YBD 94
Ø 91
P 02
Avg
Institutions – optimal care; new methods – more are detected
Influence of infection at the time of root filling on the outcome of
endodontic treatment of teeth with apical periodontitis.
Sjögren et al. 1997
55 infected
teeth
Chemomechanical
preparation, one visit
31 bacteria
free
22 with
bacteria
S1: 40% positive teeth
Root-filling
5 year
Follow up
7 failed
15 healed
29 healed
68% success rate
2 failed
94% success rate
P<0.05
Thank you!
Different methods of
radiographic follow-up methods
• Success-failure analysis
• Probability assessments
• Lesion size monitoring
• The PAI scoring system
• Quantitative methods
• New radiographic techniques
Case monitoring for
healing or retreatment
• Simple ”success/failure”-analysis in
practice
– AP development
– AP resolution
• Yes or no with
time & subject variation
Probability
assessments
Advantages: numerical, reflects subjective
variation in diagnosis
Probability assessments
Observers
Score
#1
#2
#3
#4
#5
1
16
5
1
7
6
2
5
11
16
11
9
3
1
1
5
2
0
4
1
9
7
6
7
5
24
21
18
21
25
Ørstavik et al 1986
Lesion size monitoring
• Quantitative
• Numerical, continuous scale
• Reflecting the biological process?
Lesion size
monitoring
Lesions may not
develop as ballons
growing or heal
by apposition from
within the shell of
the bony lesion.
3
11
ImageJ
From Friedman et al 1997
14
Use of microbial markers
• Endodontics is the prevention or treatment of
apical periodontitis
• Apical perio is caused by microbial infection of
the root canal system
• Presence of cultivable bacteria at the time of
filling is directly associated with the probability
of healing
• Can we use microbial sampling as a tool
predicting long-term outcome?
Bacteriological sampling procedures:
Complete vs. discrete
Growth after extensive
reaming: a clinical pilot
Sample
A
D1
D2
R1
On admission
First reamer to bite
Final reamer, complete apical circle
Second appointment, next reamer up
Ørstavik et al. 1991
6
5
Growth
after
extensive
reaming:
log10
values
4
3
2
1
0
A
D1
D2
ISO 40-
R1
ISO 45+
Ørstavik et al. 1991
1996 05
1997 08
1997 12
1999 05
1999 05
2000 05