THE COURSE OF the last twenty years, Barry Musikant and I have published
well over 125 articles in the top dental journals around the world.
We have had articles about posts, cores, endodontics, composites, and even
hand cream published in journals ranging from the Journal of Dental Research,
the Journal of Prosthodontics, and the Journal of Endodontics, to Dentistry
Today. But just recently, we published what I consider to be one
of the most interesting and relevant articles we have written in the last
twenty years. The article, “A study of one-visit treatment using
EZ-Fill root canal sealer” was published in the June 2001 issue of Endodontic
Practice. This article is important for us on two levels. First,
it validates the clinical techniques of doing endodontics in one visit
and using the EZ-Fill technique. Second, it gives us a yardstick
to measure how well we are doing for our patients (your patients) on a
success-versus-failure level. I find it interesting to note that
we could practice for more than 25 years and not know scientifically how
successful our treatment has been for our patients. We could know
it empirically from what we saw on a daily basis in our office, but here
is our first opportunity to actually quantitatively tabulate our clinical
results. It was interesting to note that most of the failures (9
cases) were due to fractured teeth. In the remainder of this article,
I will give you the highlights of this recently published paper.
the last fifty years, endodontics has seen the advent of many new techniques
and devices that have been aimed at making the procedure easier and increasing
the success rate of the treatment. Some have worked well; others
appeared to work well when the academic literature was reviewed, but in
clinical practice success was not apparent. 1 As
with any technique in dentistry, clinical success is the acid test.
Many investigators have reviewed the literature
on endodontic success vs. failure and have reported similar ranges of results.
Pekruhn in 1986 reported on 15 studies.2 He found
a failure range of 2.3 percent to 30 percent. This corresponds to a success
range of 70 percent to 97.7 percent. Friedman in 1997 reported on
37 success vs. failure studies done from 1956 to 1996.3
He found a reported success range for these studies of 59 percent to 98
percent. Weiger et al. studied the literature and reported
a success range between 70 percent and 90 percent.4
Hepworth and Friedman reviewed studies of orthograde retreatment and found
a range of success of 70 percent to 90 percent.5
Success for single-visit endodontic treatment falls
in the high end of the ranges studied by these authors. Pekruhn reported
a failure rate of 5.2 percent or a success rate of 94.8 percent in his
study on one-visit root canals. 2 Soltanoff in his single-visit
study reported a success rate of 85 percent.6 Oliet reported
a success rate of 89 percent for single visit endodontic treatment,7
and Jurcak et al. in their one-visit study on soldiers also reported a
success rate of 89 percent.8
Naturally, the optimum success rate, the one
we all strive for, is 100 percent success. Unfortunately, there are
too many variables in treatment, materials, diagnosis, and reporting methods
to make this a reality. Certainly new endodontic techniques that
report success rates in the high end of the ranges previously reported
should be considered clinically successful treatments.
Obturation of the root canal space has always
been an arduous task with unpredictable results in two aspects. One
aspect is how to thoroughly fill the canal lumen and the other is how to
accurately and repeatedly place the root canal filling to the anatomic
apex of the root. Poor results in either of these two critical areas
can ultimately lead to endodontic failure.6,7
A new obturation technique, EZ-Fill epoxy resin
root canal cement and bi-directional spiral system from Essential Dental
Systems (S. Hackensack N.J.) has been developed. This technique achieves
the desired results in a predictable easy fashion. The aim of this
study is to evaluate completed EZ-Fill endodontic cases for a successful
outcome over a six-month to two-year time period.
Materials and Methods
TEST SAMPLE consisted of 145 patients seen in a private endodontic practice
in New York, New York. Non-surgical root canal therapy was performed on
153 teeth in one or more visits during the time period from 1/1/97 to 12/31/97
by three endodontic practitioners. Each endodontic specialist had more
than twenty years of experience in a “very New York City” endodontic practice.
The following patient factors were also collected:
age; sex; whether or not the tooth was vital; if non-vital, whether there
was PAR (periapical area of radiolucency); number of visits to complete
treatment (1, 2, or more); radiographic findings; type of failure; fracture
status; extraction status.
The instrumentation technique for the endodontic
procedure was the same in all teeth studied. All teeth were treated
with a rubber dam in place using an aseptic technique. Access was achieved
and the working length was determined using the Endex apex locator (Osada,
Los Angeles, CA) During instrumentation the canals were irrigated
frequently with 2.5 percent sodium hypochlorite. The apex was instrumented
to a size #20 stainless steel .02 tapered instrument. Next the canal
was widened with a number 2 Peeso reamer, no closer than 3 mm from the
apex. Thereafter the step-back technique was used to taper the canal.
A size #25 stainless steel Flexo-reamer (Dentsply/Maillefer, Tulsa OK)
was used 1 mm short of the apex. Then a size #30 stainless steel
flexoreamer was used 2 mm short of the apex. Next a size #35 stainless
steel flexoreamer was used 3 mm short of the apex. Then a size #40
stainless steel flexoreamer was used 4 mm short of the apex and finally
a size #45 stainless steel flexoreamer was used 5 mm short of the apex.
Once the canal had been grossly prepared, either
an .06 or .08 nickel titanium file of greater taper (Dentsply, Tulsa OK)
was used to give the final shape to the canal. This sequence of instrumentation
is known as the “Simplified Endodontic Technique” or S.E.T.9-11
The canal was then filled with either a fine-medium or medium gutta-percha
The canal was obturated using the EZ-Fill system,
which consists of a bi-directional spiral paste filler and epoxy root canal
cement. The cement is an epoxy resin based cement like AH-26 but
much more radiopaque. It is also very biocompatible.9-11
The bi-directional spiral of this system ensures that the canal walls are
covered with cement and that there is no or minimal cement past the apex.
This controlled coverage is achieved because the spirals at the coronal
end of the instrument spin the cement down the shaft toward the apex while
the spirals at the apical end spin the cement upward toward the coronal
end. Where they meet (about 3-4 mm from the apical end of the shaft),
the cement is thrown out laterally (Figure 1). A prefitted single
gutta-percha point was placed to the apex. The tapered shape of the
canal lets the excess cement escape coronally. The cement in the
canal seals the apex and all lateral and accessory canals. 12
The excess gutta-percha was seared off, and the access cavity was sealed
with either glass ionomer cement or zinc phosphate cement.
At the end of the appointment, the patient was given
both the cardiac dosage of antibiotic and 600 mg of ibuprofen for pain
management. The patient was then instructed to return to his or her
general dentist, who would restore the tooth.
Clinical and Radiographic Examination
RECALL CARDS were sent and telephone reminders were made to 363 patients.
We were able to recall and evaluate 153 treatments in this study.
At the recall examination, from six to twenty-four months after
treatment, we recorded pain; tenderness to percussion, palpation, or both;
fistula development; and swelling. Radiographic examination, using
the long cone technique with a Siemens Heliodent x-ray unit, was carried
out using an x-ray film positioning device by Rinn (Rinn Corp., Elgin IL).
Success was defined as:
• On radiograph a preexisting lesion had gotten smaller or healed completely.
• On radiograph no new lesion had formed where there was no lesion
• The patient upon questioning at the recall examination was asymptomatic.
• The patient was functioning well with the tooth.
All radiographs were examined by a single endodontist, and patients
were clinically examined at recall by the endodontist who did the treatment.
THE FISHER EXACT TEST was used to determine whether outcome (success,
non-success), was associated with sex, number of visits, vital status,
and, among non-vital teeth, presence of PAR. Due to the small number
of unsuccessful outcomes, a multivariate analysis could not be carried
RECALL CARDS were sent and telephone reminders were made to 363 patients.
We were able to recall and evaluate 153 treatments in this study.
This was a recall rate of 42 percent.
MEAN AGE of the patients was 53 and ranged from 20 to 85. There
were 61 percent females and 39 percent males in the study. There
were 57.2 percent vital teeth and 42.8 percent nonvital teeth in the study.
Of the non-vital teeth, 66 percent did not have a PAR and 34 percent did
THE OVERALL TREATMENT estimated success rate was 94.1 percent.
This was found at the exact 95 percent confidence interval: 89.1 percent
to 97.2 percent. There was a frequency of 9 unsuccessful and 144
successful endodontic treatments.
There was strongly no significant association between
success rate and each of the following variables:
|number of visits
||P = 0.442
||P = 0.757
||P = 0.707
Therefore there was a 94.1 percent success rate regardless of whether
treatment took one or more visits, whether the tooth was vital or nonvital,
and whether the patient was male or female.
IT WAS STRONGLY FELT that clinical success was an important aspect of
a successful outcome. Success rates reported over the last twenty
years have ranged from 78 percent to 95 percent. Our result of 94.1 percent
success fits well within this range. Differences in the definition of success
most probably would alter the overall result of each study.
However, it is difficult to determine by how much each study’s results
would change. Our feeling is that individual studies may change slightly,
but the overall range would most likely be the same due to other variables.
These other variables include the skill of operators, who and how many
people review the x-rays and cases, the techniques used, the materials
used, and the time frame of the recall exam.
In this study, three endodontists who each have
more than twenty years of experience in private practice treated all the
patients. This high level of clinical experience could possibly be
one reason the success rate was on the high end of the scale. In
a study by Sjogren et al., undergraduates at the University of Umea did
the endodontic therapy and had a 91 percent success rate. 13
We used one endodontist to read the x-rays and evaluate the patients clinically.
This helped reduce the variable of different opinions by different evaluators
as described in the articles by Goldman and Seltzer.14,15
The authors tried to eliminate the variables of
technique and materials in this study by using the same instrumentation
technique and materials for each patient. We followed the S.E.T.
technique for instrumentation and used the EZ-Fill epoxy resin root canal
cement and bi-directional spiral obturation technique with a single gutta-percha
point. Friedman et al. reported on a clinical study to assess the
treatment results following endodontic therapy using a glass ionomer cement
sealer (Ketac-Endo, ESPE Gmbh, Seefeld, Germany).16 They
found a 78.3 percent success rate and concluded that their results were
compatible with those found in the literature and that this supports the
clinical use of Ketac-Endo as an acceptable endodontic sealer.
In this study, EZ-Fill epoxy resin root canal cement
(a derivative of AH 26 root canal cement) was used; Figure 5B illustrates
complete resorption of excess cement after a two-year recall.
The recall time frame shows the majority of patients
at six months, with the next highest groups at one-year and two-year recalls.
We were able to recall and evaluate 153 treatments
out of 363 in this study. This was a recall rate of 42 percent.
This correlates well with a mean recall rate of 43 percent for other studies
as reported by Pekruhn.3
In agreement with other studies, there was strongly
no significant association between success rate and:
• the number of visits
• patient sex
Whether the tooth was treated in one visit or in
more than one visit did not affect the success rate. Teeth treated
in one visit were equally as successful as teeth treated in more than one
visit. Whether the tooth was vital or nonvital did not affect the
success rate, and whether the patient was male or female did not affect
the success rate in this study.
Interestingly, in a study by Vire of 116 extracted
endodontically treated teeth, failure that led to extraction of these teeth
occurred due to endodontic causes in only 8.6 percent of the population.
A SUCCESS RATE of 94.1 percent was found for this study using the EZ-Fill
bi-directional spiral and epoxy resin root canal cement to obturate the
canals. This correlates very well with reported success rates of
between 78 percent and 95 percent in other studies.
There was no significant association between success
rate and each of the following variables: number of visits, sex, and vitality.
These results support the clinical use of the EZ-Fill obturation system
as an acceptable endodontic technique and sealer.
Orstavik D, Kerekes K, Eriksen HM. Clinical performance of three endodontic
sealers. Endod Dent Traumatol 1987; 3:178-86.
Pekruhn, RB. The Incidence of Failure Following Single-visit Endodontic
Therapy. J Endodon 1986; 12:68-72.
Friedman S. Success and Failure of Initial Endodontic Therapy. Ontario
Dentist 1997; 74:35-38.
Weiger R, Axmann-Kremar D, Lost C. Prognosis of conventional root
canal treatment reconsidered. Endod Dent Traumatol 1998; 14:1-9.
Hepworth M, Friedman S. Treatment Outcome of Surgical and Non-Surgical
Management of Endodontic Failures. Journal of the Canadian Dental Association
Soltanoff W. A Comparative Study of the Single-Visit and the Multiple-Visit
Endodontic Procedure. J Endodon 1978; 4:278-281.
Oliet S, Single-visit Endodontics: A Clinical Study. J Endodon 1983;
Jurcak JJ, Bellizzi R, Loushine R. Successful Single-Visit Endodontics
During Operation Desert Shield. J Endodon 1993; 19:412-413.
Musikant BL, Cohen BI, Deutsch AS. Rethinking endodontics: Attaining total
obturation of the root canal system with a simplified system. General
Dentistry 1999; Jan-Feb: 73-82.
Seidman D. A General Dentist’s Viewpoint of Two New Endodontic Techniques.
1999; 20: 921-932.
Musikant BL, Cohen BI, Deutsch AS. Report of a Simplified Endodontic Technique.
1999; 20: 1088-1094.
Cohen BI, Pagnillo MK, Musikant BL, Deutsch AS. The evaluation of apical
leakage for three endodontic fill systems. General Dentistry,1998;
Sjogren U, Hagglund B, Sundqvist G, and Wing K. Factors Affecting the Long-term
Results of Endodontic Treatment. J Endodon 1990; 16:498-504.
Goldman M, Pearson AH, Darzenta N. Endodontic success: who’s reading the
radiograph? Oral Surg 1972; 33:432-7.
Seltzer S, Bender IB, Smith J, Freidman I, Nazimov H. Endodontic failures-an
analysis based on clinical, roentgenographic, and histologic findings.
Part II. Oral Surg 1967; 23:517-30.
Friedman S, Lost C, Zarrabian M, Trope M. Evaluation of Success and Failure
after Endodontic Therapy Using a Glass Ionomer Cement Sealer. J Endodon
Vire DE. Failure of Endodontically Treated Teeth: Classification and Evaluation.
Endodon 1991; 17:338-342.
FIGURE 1: The EZ-Fill bi-directional
spiral spinning the cement laterally, not apically.
FIGURE 2A: Tooth number 30,
old root canal, under treated and underfilled.
FIGURE 2B: Root canal retreated
and refilled using EZ-Fill obturation technique.
FIGURE 2C: Two-year recall
showing complete healing.
FIGURE 3A: Typical vital
case at completion. No periapical pathology.
FIGURE 3B: Six-month recall
showed no pathology developed, healed and asymptomatic.
FIGURE 4A: Typical completion
x-ray of a one-visit vital case using the EZ-Fill obturation technique.
FIGURE 4B: Nine-month recall
x-ray showing intact lamina dura and healing.
FIGURE 4C: Two-year recall
x-ray showing normal bone anatomy being maintained.
FIGURE 5A: Tooth number 15
showing excess EZ-Fill epoxy resin cement past the apex of the palatal
FIGURE 5B: Two-year recall
x-ray showing complete resorption of cement and healing.