Endodontic success-Who’s reading the
radiograph?
Melvin Goldman, D.D.S.,” Arthur H. Pearson, D.N.D.,‘*
Nicholas Dnrzenta, D.D.S., D.X.D.,‘“”
Boston, Mass.
TUFTS
USIVERSITY
SCHOOL
OE’ DENTAL
and
MEDICINE
Success and failure
in 253 cases selected
at random
were
the films and having
six examiners
read them,
independently
ing one another.
They agreed
on fewer
than half of the
was only one of determining
whether
or not an area of
on one film, the agreement
was still less than half. Upper
percentage
of disagreement,
but all the other teeth gave
agreement
also.
T
determined
by mounting
and without
consultcases. When the question
rarefaction
was present
molars
gave the greatest
large percentages
of dis-
he endodontic literature
is replete with success and failure studies. Those
of Strindberg,l
Bender and associates,* Storms,3 and Heling and Tomshe are
representative
examples of some of the more recent ones. All of the authors
exa.mined the success and failure percentages from various aspects. Strindberg
studied the overfilling-underfilling
asp&,
whereas Bender and Seltzer studied
t’he positive or negative culture aspect. Others compared silver cones and guttapercha fillings. Each group was meticulous in its approach and carefully
reported its findings. However,
most of the results were based on the interpretation of radiographs,
and upon this rather
questionable
foundation
the
whole structure of each study was based.
Anyone who has rendered endodontic therapy knows that on many occasions the radiograph
is misleading. Is there an area of radiolucency?
Where
is the apex of the root? How large is the area? These and many other problems
trouble all of us each day, Bender and Seltzer5 have shown in their study of
radiographic
diagnosis that, unless an area of bone destruction
encroaches
on the cortical plate, it is usually not evident on a radiograph.
*Associate
**Professor
***Associate
432
Clinical
Professor
in Endodontics.
and Chairman
of Department
of Endodontics.
Professor
in Radiology.
Volume 33
Number 3
Radiographic diagnosis in endodontics
433
Table I
Observer
Success
FCLilzlV~
203
6
12
9
41
28
48
1
189
4
5
6
199
170
202
162
Questionable
The following study was designed to investigate the reliability
graphic diagnosis.
44
52
45
42
23
43
of radio-
METHODS AND MATERIALS
Two hundred fifty-three cases from the files of an active endodontic practice were selected at random. The criteria used were: (1) All the teeth were
comfortable, asymptomatic, and without fistulas. i2) Both a radiograph of the
completed root canal filling and a checkup radiograph taken at least 6 months
after completion were available.
The cases were selected completely at random; the person selecting the
caseswas not told the purpose for which they were to be used. The radiographs
were mounted and numbered, and the status of the pulp at the beginning of
treatment was recorded. The radiographs were then read and recorded completely independently of one another by six different examiners. The following
criteria for successand failure were established :
I.
Vital pulp
A. Success-No area at beginning, no area on checkup
B. Failure-No area at beginning, area on checkup
II. Pulpless-without
area
A. Success-No area at beginning, no area on checkup
B. Failure-No
area at beginning,
area at checkup
III. Pulpless-with area
A. Success-Area at beginning, area healed or definitely smaller at
checkup
B. Failure-Area
at beginning, area larger at checkup
IV. Questionable
A. Cannot decide whether area is present
B. Cannot decide whether area is larger, smaller, or samesize
C. Bad film
The examiners were two endodontists, one with 25 years of experience, the
other with 20; an associate professor of radiology; and three second-year
graduate endodontic students .# The results were analyzed and catalogued.
RESULTS
There were 253 cases: 159 teeth were pulpless, and 94 were vital.
Table I shows the total number of successes,failures, and questionables of
*Dr. Alan L. Levick, Dr. Paul 5. Scols, and Dr. Hugh Tresnor.
Table
II
each examiner. The number of failures ranged from six to forty-eight.
The
number of questionables ranged from twenty-three to fifty-two.
The examiners were asked to judge only the completed films of the 159
pulpless cases (not the checkup films) and to determine whether there was
an area of rarefaction. The results varied from twenty-eight teeth without an
area to seventy-six without an area (Table II).
If we continue the breakddwn further in order to ascertain whether there were
certain cases which were confusing to all, the analysis showed that, in a
consideration of the success-failure-questionable category only, all six examiners
agreed on 119 of 253 cases, or 47 per cent of the time. If we look at the
casesin which five of the six examiners agreed, there were fifty-two additional
casesfor a total of 171 of 253, or 67 per cent.
If we consider the pulpless cases and those in which a single judgment of
one film was involved, the six examiners agreed sixty-seven out of 159 times,
for a total of 42.1 per cent. Again if we consider the cases in which five of the
six agreed, there were forty-seven additional cases for a total of 114, or
71 per cent.
If we combine Tables I and II, all six examiners agreed (in the successfailure-questionable category plus the pulpless with or without area) in seventyseven of 253 cases, or 30.4 per cent,. Again, five out of six agreed in an
additional fifty-seven casesor 134 of 253, or 53 per cent of the time.
Since it might be thought that six examiners were too many, the results
were analyzed for two groups of three examiners. Examiners No. 1, 2, and 3
in the success-failure-questionable category agreed in 165 of 253 cases, or 65
per cent of the time. If we consider only the pulpless with or without area,
they agreed in ninety-eight of 159 cases,or 61 per cent of the time.
The second group consisting of Examiners No. 4, 5, and 6 agreed in the
success-failure-questionable category in 143 of 253 cases, or 56 per cent of
the time. In the pulpless with or without area, they agreed in 104 of 159 cases,
or 65 per cent of the time.
Even further, if we consider only two of the examiners, No. 4 and No. 6
(selected because they were the most critical of all the examiners), they
agreed in the success-failure-questionable category in 187 of 253 cases, or
73 per cent of the time. In the pulpless category, they agreed in 125 of the
159 cases,or 78 per cent of the time.
Of the total of 253 cases, there were 109 which everyone agreed were
Volume
Number
33
3
Radiographic
diagnosis
in endodontics
435
Table III
Upper
Agreed
15
Lower
Agreed
2
anterior
Disagreed
11
anterior
Disagreed
2
VITAL
Upper
Agreed
6
Lower
Agreed
7
CASES
premolar
Disagreed
8
premolar
Disagreed
5
Upper
Agreed
3
Lower
Agreed
11
molar
Disagreed
14
molar
Disagreed
11
Upper
Agreed
28
Lower
Agreed
6
anterior
Disagreed
34
anterior
Disagreed
9
PULPLESS
CASES
Upper
premolar
Agreed
Disagreed
14
17
Lower
premolar
Agreed
Disagreed
8
4
Upper
Agreed
5
Lower
dgreed
14
molar
Disagreed
10
molar
Disagreed
9
successful,
seven cases which everyone agreed were questionable,
and three
cases which everyone agreed were failures.
Table III is a breakdown
of the various teeth involved. The upper molars
were the most difficult for everyone to reach agreement upon. But even in upper
anterior teeth in the pulpless categories, more cases were disagreed upon than
were agreed upon.
DISCUSSION
It is clear that the radiograph
is a very questionable means of determining
success and failure. This is not surprising,
for we interpret
radiographswe do not read them. To read is to see a group of letters that make up a word.
Everyone sees the same letters and reads them. Radiographs
have to be interpreted, and so many factors and variables enter into what we see that the
whole procedure
becomes exceedingly
confusing.
For instance, the mental
state of the examiner is involved-Was
he tired? Was he upset by a quarrel?
Did he view the films in the morning or at night? What instructions
were
given to him? Factors such as these may enter into the interpretation
that
he renders.
The results speak for themselves. In the success-failure-questionable
category,
a judgment
and comparison had to be made. That is, both radiographs
had
to be interpreted
and a judgment made for each, and then one had to be
compared to another. This resulted in 47 per cent agreement. Even when we
required only five of six examiners to agree, we still had only 67 per cent
agreement.
It might be said that this is possible because of the probability
of difference
in the density of the film, the angle of the primary beam, possible differences in
developing and fixing, etc. However,
every examiner was looking at the same
films, so that angulation, density, etc., would tend to cancel out. But, if we
assume that there is merit to the above-mentioned
objections, consider Table
II. Here no comparison was involved. Only one judgment
on one film had
to be made-whether
an area was or was not present. And the puzzling thing
436
Goldman,
Oral
March,
Pea,rson, u?ld Darxenta
Surg.
1972
is that there was only 42.1 per cent agreement by all six examiners. This uas
slightly
less than tht sncc.ess-faill~re-qnestionahlc
category in whicl~ ;I cornparison was involved.
Reducing the number of examiners did raise the percentage of agrremcnt
somewhat, but not anywhere near reliable levels. Only two thirds of the time
did three examiners agree.
Going even further and reducing the number of examiners to two and even
select,ing the two most critical ones (No. 4 and No. 6) raised the agreement
level of the success-failure-questionable
category to 73 per cent. They disagreed on sixty-six
cases! In the pulpless category they agreed only 78 per
cent of the time and disagreed on thirty-eight
cases!
It is interesting
that the examiner who found only six failures was the
one who had treated a large number of the patients. The two examiners who
found nine and twelve failures also had treated many of the patients. The
other three who found twenty-eight,
forty-one, and forty-eight
failures had not
treated any of the patients. The examiner who found forty-eight
failures was the
radiologist, who, by training, considered factors which the endodontists did not.
Table III indicates the location of teeth and shows that upper molars were
the most difficult ones to agree upon. But even upper anterior
and lower
anterior teeth, which should be the easiest of all teeth to obtain good, clear films
of showed a large percentage of disagreement.
What this means in terms of success and failure
studies is unclear.
Should several persons evaluate all films? Should they confer and reach a
consensus? If one of the group is a dominant personality
by virtue of training
or position, will this influence the others? These and many other questions remain unanswered,
but all future studies must take these factors into consideration.
Further
analyses of these films are being made at present and will hc
reported at a later date.
SUMMARY
Success and failure of 253 cases selected at random were determined by
mounting the films and having six examiners read them. All examiners read
the films independently and without consulting one another. They agreed on
less than half of the cases. When the question was only one of determining
whether an area of rarefaction was or was not present on one film, the
agreement was still less than half. Upper molars gave the greatest percentage
of disagreement, but all the other teeth gave large percentages of disagreement
also.
the
The authors
wish to acknowledge
Wistar
Polytechnic
Institute
the invaluable
Computer
Center
assistance
of Mr. Richard
in compiling
the data
J. Schwartz
of
for this study.
REFERENCES
1. Strindberg,
L. 2.: The Dependence
of the
Acta Odontol.
Stand.
14 Supp. 21, 1957.
2. Bender
I. B., Seltzer,
S., and Turkenkopf,
18: 52s540,
1964.
Results
S.:
of Pulp
To Culture
Therapy
or Not
on Certain
to Culture,
Factors,
ORAL
SURG.
Volume
Number
Ra,diographic
33
3
diagnosis
in endodontics
That
Influence
the Success
of Endodontic
3. Storms,
J. L.: Factors
Dent. Assoc. 35: 83, 1969.
Evaluation
of Success
of Endodontically
4. Heling,
B. and Tomshe,
A.:
ORAL SURG. 30: 533-536,
1970.
5. Bender,
I. B. and Seltzer,
S.: Roentgenologic
and Direct
Observations
Lesions
in Bone, J. Am. Dent. Assoc. 62: 152-160,
1961.
Reprint
requests to:
Dr. Melvin
Goldman
Department
of Endodontics
Tufts
University
School of Dental
136 Harrison
Ave.
Boston,
Mass. 02111
Medicine
Treatment,
Treated
of
437
J.
can.
Teeth,
Experimental
0
