Treatment of a second maxillary molar with six canals.

Abstract

Variations in the dental anatomy are found in all teeth. Knowledge of these variations, particularly concerning the location and treatment of all canals, is very important for the success of the endodontic therapy. The purpose of this study is to present a clinical case of a maxillary second molar with three palatal canals, two mesio-buccal and one disto-buccal canal. This report serves to remind clinicians that such anatomical variations should be taken into account during endodontic treatment of the maxillary molars.

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Aust Endod J 2007; 33: 42–45
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© 2007 The Authors
Journal compilation © 2007 Australian Society of Endodontology
Blackwell Publishing IncMalden, USAAEJAustralian Endodontic Journal1329-1947© 2007 The Authors; Journal compilation © 2007 Australian Society of Endodontology? 2007••••4245Case Report Six-Canalled
Maxillary Second MolarB. Pasternak Júnior et al.
CASE REPORT
Treatment of a second maxillary molar with six canals
Braulio Pasternak Júnior, DDS, MSc1,3; Cleonice da Silveira Teixeira, DDS, MSc2,3; Ricardo Gariba Silva, DDS, PhD3;
Luíz Pascoal Vansan, DDS, PhD3; Manoel D. Sousa Neto, DDS, PhD3
1 Faculty of Dentistry, UNISUL, Tubarão, Santa Catarina, Brazil
2 Faculty of Dentistry, UFSC, Florianópolis, Santa Catarina, Brazil
3 Faculty of Dentistry, UNAERP, Ribeirão Preto, São Paulo, Brazil
Abstract
Variations in the dental anatomy are found in all teeth. Knowledge of these vari-
ations, particularly concerning the location and treatment of all canals, is very
important for the success of the endodontic therapy. The purpose of this study is
to present a clinical case of a maxillary second molar with three palatal canals,
two mesio-buccal and one disto-buccal canal. This report serves to remind clini-
cians that such anatomical variations should be taken into account during
endodontic treatment of the maxillary molars.
Keywords:
anatomical variations, maxillary molars, root
anatomy.
Introduction
The treatment of the entire root canal system is essential to
maximise the possiblility of obtaining success in the endo-
dontic therapy. It is necessary for the clinician to have a
thorough knowledge of the dental anatomy, as well as of
its variations.
Pécora et al. (1) studied the internal anatomy of 370
maxillary molars by diaphanisation and found that the
maxillary first, second and third molars displayed three
canals in 75%, 58% and 68% of the teeth respectively,
while there were four canals in 25% of maxillary first
molars, in 42% of second molars and in 32% of third
molars. The fourth canal was found in the mesio-buccal
root of the teeth in 100% of these cases.
Most studies in anatomical variations of maxillary molar
teeth appear to deal with the first molar. There are refer-
ences to teeth with four to six canals, and in the mesio-
buccal and in the palatal roots, the number of canals can
vary between one and three (2–8). There are also reports
of two canals found in the disto-buccal root (9,10).
Anatomical variation studies in the second maxillary
molars are not so numerous. Fava et al. (11) reported the
presence of just one canal and one root in the second max-
illary molars of the same patient, while Alani (12) encoun-
tered four roots in the second maxillary molars of the same
patient bilaterally. Baratto-Filho et al. (13) carried out an
in vitro study of two maxillary second molars with four
canals and two different palatal roots. In the same year,
Barbizam et al. (14) reported a similar study of a second
maxillary molar also with four canals in four distinct roots.
It is worth mentioning that Benenati (15) presented a
clinical case of a second maxillary molar with two palatal
roots and a groove located at the side of the tooth.
The purpose of the present study is to report a clinical
case of a second maxillary molar with six canals.
Case report
A 51-year-old male patient with melanoderma was
directed to the dental clinic with acute irreversible pulpitis
in the right second maxillary molar.
A preoperative radiograph (Fig. 1) was taken and, after
anaesthesia and rubber dam placement, a conventional
coronal access was made. It was initially possible to locate
the mesio-palatal canal as well as the mesio-buccal, disto-
buccal and palatal canals. These four canals were explored
using a size 15 Flexofile file (Dentsply-Maillefer, Bal-
laigues, Switzerland). After the cervical preparation of
the canals with Gates-Glidden drills numbers 1 and 2
(Dentsply-Maillefer, Ballaigues, Switzerland), a bleeding
occurred at the centre of the pulp chamber floor. After the
irrigation with 1% sodium hypochlorite (Dermus, Flori-
anópolis, Brazil) and aspiration, two more orifices were
discovered. These orifices were also explored and two
more palatal canals were detected. Although being dis-
tinct, the canals were not very well defined due to a flat-
tening of their outlines (Fig. 2). The radiographs taken
Correspondence
Dr Braulio Pasternak Júnior, Avenida Madre
Benvenuta, 1285 – Santa Mônica, Florianópolis,
Santa Catarina, Brazil CEP:88035-000. Email:
bpasternak@terra.com.br
doi: 10.1111/j.1747-4477.2007.00059.x

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B. Pasternak Júnior et al.
Six-Canalled Maxillary Second Molar
© 2007 The Authors
Journal compilation © 2007 Australian Society of Endodontology
43
during the working length determination (Figs. 3,4) aided
in the understanding of the internal anatomy of this tooth
and were taken with size 15 Flexofile files in the canals.
The appointment was then concluded with the insertion
of intra-canal corticosteroids (Otosporim, GlaxoWell-
come, São Paulo, Brazil).
After 3 days, the correct working lengths of each canal
were established by means of an apex locator (Bingo 1020,
Engineering Technologies Forum, Rishon-Lezion, Israel).
Biomechanical preparation was performed with a size
35 file for the buccal canals and size 40 file for the palatal
canals. Calcium hydroxide (Calem, SS White, Rio de Jan-
eiro, Brazil) was used as the intra-canal medicament and it
remained therein for 7 days. All canals were obturated
with gutta-percha cones (Tanari, Manacapuru, Amazonas,
Brazil) and Sealapex sealer (Sybron Endo, Glendora, CA,
USA) using the Tagger hybrid technique (Figs. 5,6). The
patient returned after 1 year for the clinical and radio-
graphic follow-up (Fig. 7).
Discussion
Based on the literature and this clinical case, it is evident
that knowledge of the anatomical variations of the maxil-
lary molars is extremely important for the success of end-
odontic treatment. According to Cohen and Burns (16),
canals are often not treated because they are not located.
Figure 1 Preoperative radiograph.
Figure 2 Illustration showing the location of orifice openings: mesio-
buccal (black circle), mesio-palatal (white circle), disto-buccal (triangle),
palatal (square) and palatals with orifice opening in the pulp chamber
(cross).
Figure 3 Radiographs taken during length determination.
Figure 4 Further radiographs taken during length determination.

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© 2007 The Authors
Journal compilation © 2007 Australian Society of Endodontology
Six-Canalled Maxillary Second Molar
B. Pasternak Júnior et al.
The clinician should give special attention to the evi-
dence of the occurrence of anatomical variations through-
out the procedure. In the present case, during access,
removal of the coronal pulp and exploration of the canals,
the presence of the bleeding on the pulp chamber floor
was indicative of more canals and aided in the location of
the two remaining palatal canals. Although they had three
different orifice openings, these canals had a single apical
foramen. The two mesio-buccal canals of the mesio-buccal
root had separate apical foramina.
Despite Krasner and Rankow (17) having defined the
laws of orifice location of the root canals, drawing conclu-
sions that the orifices of the root canals are always located
at the junction of the walls and the floor, at the angles in
the floor-wall junction and at the terminus of the root
developmental fusion, in the case described herein and as
shown in Figure 2, two palatal canals were located at the
centre of the pulp chamber floor. Despite such general
suggestions about access, it is most important that careful
attention is paid to any evidence of additional canals.
A palatal root with two or more different canals has
rarely been described (13,14,18). The current study
showed the presence of three palatal canals, although in
the final radiograph, two canals are more clearly observed,
probably due to the flattening of these canals centrally
located on the pulp chamber floor.
Another outstanding clinical observation in this case
report is the length of the tooth, which was 26 mm; this
value being an above-average length for second maxillary
molars that have a maximum reported length of 24 mm
(16). The length of the tooth can hinder the biomechanical
preparation and filling.
The possibility of a palatal root with one or more canals,
as well as the existence of two palatal roots should be con-
sidered when treating maxillary second molars. A variety
of radiographic angulations should be used and, if this
anomaly is confirmed, a broad coronal access will allow for
correct localisation of root canals. Furthermore, the clini-
cian should be attentive to the signs of anatomical varia-
tions, as in the present case, where the pulp chamber floor
bleeding revealed the presence and the location of the pal-
atal canals.
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Figure 5 Fitting of gutta-percha points of the six root canals. Two palatals
with orifice opening in the pulp chamber (arrow).
Figure 6 Obturation radiograph.
Figure 7 One-year radiographic follow-up.

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Six-Canalled Maxillary Second Molar
© 2007 The Authors
Journal compilation © 2007 Australian Society of Endodontology
45
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