Bilateral Mandibular Canines with Two Roots and Two Separate Canals-Case Report

Knowledge of root canal anatomy is mandatory for the success of endodontic treatment. In most cases, the mandibular canines present only one root (1-5). The occurrence of two roots and even more two root canals is rare, ranging from 1% (4) to 5% (5). Despite the low prevalence, clinicians should consider the possible variations in the number of roots and root canals of mandibular canines. This paper reports the case of a patient with bilateral mandibular canines with two roots and two root canals.


INTRODUCTION
Knowledge of root canal anatomy is mandatory for the success of endodontic treatment.In most cases, the mandibular canines present only one root (1)(2)(3)(4)(5).The occurrence of two roots and even more two root canals is rare, ranging from 1% (4) to 5% (5).Despite the low prevalence, clinicians should consider the possible variations in the number of roots and root canals of mandibular canines.This paper reports the case of a patient with bilateral mandibular canines with two roots and two root canals.

CASE REPORT
A healthy 40-year-old Caucasian female was The mandibular canine is usually considered a single-rooted tooth with a single root canal.However, two canals and more rarely two roots may also occur.This paper reports the case of a patient with bilateral mandibular canines with two roots and two root canals.
The initial periapical radiographs of the mandibular right and left canines for endodontic treatment revealed the presence of two roots in each tooth.After coronal opening, the cervical third was prepared with a SX file of the ProTaper ® system and root canal length was confirmed using Root ZX electronic apex locator.Root canal preparation was completed with the series of ProTaper ® instruments and the root canal was filled with gutta-percha and an epoxy resin-based endodontic sealer according to Tagger's hybrid technique.The final radiographs showed two well-obturated canals ending at the electronically located apexes.The 6-month posttreatment follow-up showed apparent clinical and radiographic success.Clinicians should always consider the presence of anatomical variations in the teeth during endodontic treatments.Despite the low prevalence, variations may occur in the number of roots and root canals of mandibular canines, as demonstrated in this case report.
referred to the Clinic of Endodontics of Bauru Dental School, University of São Paulo for endodontic treatment of the mandibular canines and a mandibular lateral incisor for prosthetic rehabilitation.Initial periapical radiographic examination revealed the presence of two roots on both mandibular canines (Fig. 1).Endodontic treatment was performed in a single session because the teeth presented pulp vitality on clinical examination.After local anesthesia bilaterally, a rubber dam was placed and endodontic access was performed with a #1014 round diamond bur (KG Sorensen, São Paulo, SP, Brazil) and an Endo Z tapered safe-end bur (Dentsply/Maillefer, Ballaigues, Switzerland).Location and negotiation of root canals were done with a size 10 K-file (Maillefer, Ballaigues, Switzerland).The cervical and middle thirds were prepared with a

Braz Dent J (2009) 20(1): 84-86
SX file of the ProTaper ® system (Dentsply/Maillefer).Root canal length was determined radiographically and confirmed with an electronic apex locator (Root ZX; J Morita Co, Kyoto, Japan).Chemomechanical preparation was performed with hand Flexofile files (Maillefer) and irrigation with 1% sodium hypochlorite at each change of file.The instrumented root canals were filled with gutta-percha cones and an epoxy resin-based root canal sealer (Sealer 26; Dentsply/Maillefer) according to Tagger's hybrid technique (Figs.2a and 2b).The final radiographs showed two well-obturated canals ending at the electronically located apexes.The 6-month posttreatment follow-up showed apparent clinical and radiographic success.

DISCUSSION
Diagnosis and identification of the number of roots and root canals are key factors for endodontic treatment.The initial radiograph is extremely important because it allows for the identification or suspicion of root and root canal anatomical variations.Bifurcations in the cervical and middle thirds may be observed ra-diographically when the x-ray incidence angle does not cause superimposition of images.In mandibular canines, bifurcation at these sites has been shown to occur in 43.1% of the situations (6).In the present case, identification of the second root was evident, especially due to absence of some teeth.However, it does not always occur.Identification of the second root is even more difficult in the presence of tooth crowding.Therefore, the radiographic image should be carefully analyzed in order to interpret and identify details that may suggest the presence of bifurcations or trifurcations, such as sudden root canal discontinuity (7).
Endodontists should always search for two canals in mandibular canines during endodontic treatment, even in single-rooted teeth.Green (2) observed two canals in a single root in 13 out of 100 mandibular canines examined.This is consistent with the findings of Hess (8), who observed two canals in 15% of the cases.Vertucci ( 9) reported the presence of two canals in 18% of the mandibular canines.Mandibular canines with two separated canals also demonstrated in a recent case report (10).
However, the presence of two roots in mandibular canines is rarely observed (11,12).Quellet (5) described the occurrence of two roots and two canals in mandibular canines in only 5% of all analyzed teeth.Laurichesse et al. ( 4) described the second root of mandibular canines in only 1% of cases.A previous study that investigated the internal anatomy, direction and number of roots and  size of 830 extracted human mandibular canines found only 1.7% of the teeth with two roots and separate two canals (13).D´Arcangelo et al. (14) reported two cases of endodontic treatment of mandibular canines with two roots.A case report of two roots in mandibular canine was also presented by Heling et al. (15), yet the tooth exhibited three root canals.To the best of our knowledge, the occurrence of bilateral mandibular canines with two roots and two separate canals, as described in the present case, has not yet be published.
Even though the most common anatomy of mandibular canines comprises a single root and a single root canal, clinicians should consider the possible variations and always search for the second root canal in teeth with either one or two roots.

Bilateral Mandibular Canines with Two Roots and Two Separate Canals -Case Report
Department of Restorative Dentistry, Endodontics and Dental Materials,Bauru Dental School, University of São Paulo, Bauru, SP, Brazil