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Year : 2022  |  Volume : 10  |  Issue : 3  |  Page : 134-139

Endodontic management of maxillary first premolars with three root canal: Two case reports

Department of Conservative Dentistry and Endodontics, MES Dental College, Perinthalmanna, Kerala, India

Date of Submission12-Jan-2022
Date of Decision15-Mar-2022
Date of Acceptance06-Jun-2022
Date of Web Publication21-Feb-2023

Correspondence Address:
Reshma Rajasekhar
Department of Conservative Dentistry and Endodontics, MES Dental College, Perinthalmanna, Malappuram District, Kerala
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/DYPJ.DYPJ_4_22

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Endodontic treatment success is obtained by thorough chemomechanical preparation and three dimensional obturation of the root canal system. Maxillary first premolar most commonly presents with two roots with two canals. The most common variation in maxillary first premolar is the presence of three canals and can be frequently missed leading to endodontic treatment failure. This case report describes two cases of endodontic management of maxillary first premolars with three canals. Additional canal was identified through exploration and multiple radiographs with mesial and distal eccentric shifts. Appropriate knowledge regarding the possible anatomic variations and good clinical skills are essential prerequisites for a successful endodontic treatment outcome. Missed canal and inadequate cleaning and shaping contributes to persistent pain, sensitivity leading to treatment failure.

Keywords: Anatomic variation, maxillary premolar, root canal, three canal

How to cite this article:
Rajasekhar R, Karathkodiyil R, Muliyar S, Thankachan RP, Sebastian VM. Endodontic management of maxillary first premolars with three root canal: Two case reports. D Y Patil J Health Sci 2022;10:134-9

How to cite this URL:
Rajasekhar R, Karathkodiyil R, Muliyar S, Thankachan RP, Sebastian VM. Endodontic management of maxillary first premolars with three root canal: Two case reports. D Y Patil J Health Sci [serial online] 2022 [cited 2023 Mar 23];10:134-9. Available from: http://www.dypatiljhs.com/text.asp?2022/10/3/134/370120

  Introduction Top

Successful endodontic treatment outcome is obtained by accurate diagnosis, thorough chemomechanical preparation and three-dimensional obturation of the root canal system. Missed canals and inadequate cleaning and shaping contributes to nearly 42% failure of endodontically treated teeth.[1] Lack of debridement in these canals will leave inflamed pulp tissue and can harbour microorganisms which leads to periapical inflammation affecting the treatment outcome. Therefore, the primary step for a successful endodontic treatment is precise diagnosis and good knowledge about the root canal system.

Maxillary first premolar is a transitional tooth between anteriors and molars which most commonly appears as two rooted teeth with two canals.[2] One of the common variation reported in maxillary first premolars is three roots with three root canals with an overall incidence rate of 1.7% ranging from 0.5%–9.2%.[3],[4] Dinakar et al. in 2018 evaluated the canal morphology in extracted maxillary first premolars using clearing technique in South Indian population and reported an incidence of 2.22% for three rooted maxillary premolars.[5] Neelakantan et al. in 2011 reported an incidence of 2.3% for three rooted maxillary premolars by assessing the canal morphology using extracted maxillary first and second premolars in Indians using canal staining and clearing technique.[6] By using CBCT analyses on extracted maxillary first premolars in Indian teeth, Karunakaran et al. in 2019 observed an incidence of 1.7% for three canals.[7]

Beltes et al. in 2017 classified the morphology of maxillary premolars based on external and internal morphology [Figure 1]. The external morphology was classified based on root separation [Table 1] and internal morphology was categorized based on shape of the buccal(B) and palatal(P) orifice at the point of bifurcation, distance from the B and P canal bifurcation from cementoenamel junction (CEJ), distance of mesiobuccal (MB)-distobuccal (DB) bifurcation from CEJ, distance between the B-P and MB-DB bifurcation and inclusion of C-shaped canals.[8]
Figure 1: Classification of external morphology of three rooted premolars (A-D); Cross-sectional CBCT images showing buccal (B) and palatal (P) orifice configurations: (E) B- triangular and P-tear shaped, (F) B- heart shaped and P-tear shaped, (G) B and P- tear shaped, and (H) B and P- oval shaped configurations[8]

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Table 1: Classification of external morphology of maxillary premolar based on root separation

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The anatomy of maxillary premolar with three canals usually appears similar to maxillary molars with distinct MB, DB and P canals. Therefore, different terminologies such as mini molars, miniature three-canalled maxillary molars, radiculous premolar has been given.[9],[10],[11] Present case report discusses the endodontic management of two cases of maxillary first premolar with three canals.

  Case Report Top

Case 1

A 27-year-old female patient reported to our department with a chief complaint of pain in relation to her upper back tooth for the past 3 days (#14). Her pain aggravated on having cold and hot fluids and relieved on its own. On clinical examination, there was class II distoproximal deep caries present and was tender on vertical percussion. Electric pulp testing showed early response and cold testing revealed severe pain which lingered for 10 seconds. Preoperative radiograph was taken which revealed distoproximal radiolucency involving pulp and widened periodontal ligament space [Figure 2]A. A clinical diagnosis of symptomatic irreversible pulpitis with symptomatic apical periodontitis was established and a conventional nonsurgical root canal therapy was advised.
Figure 2: Preoperative radiograph (A), Working length radiograph with straight (B) and mesial shift (C), master cone radiograph (D), obturation (E), radiograph after 6 months (F)

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Local anaesthesia was administered using 2% lignocaine with 1:1,00,000 epinephrine. Endodontic access cavity preparation was done using endo access # 2 (Dentsply, Maillefer, Germany) and extended using endo-Z bur (Dentsply, Maillefer, Germany). Two canals were located – buccal and palatal and on further exploration an additional split was suspected and negotiated on the mesiobuccal aspect of the buccal canal. Number 8 and 10 k-files (Dentsply, Maillefer, Germany) were used initially to negotiate the canals and RC prep was used as root canal conditioner. Working length was established by using apex locator (Root ZX; Morita, Tokyo, Japan) and reconfirmed with radiographs with straight and mesial as well as distal eccentric shifts [Figure 2]B and [Figure 2]C. Canal orifices were enlarged with Protaper gold SX (Dentsply, Maillefer, Germany). Shaping and cleaning were done till F1 rotary file with irrigation using normal saline and 3% sodium hypochlorite (Parcan, Septodont) followed by 17% EDTA (Md cleanser, Meta biomed) in between and final irrigant used were 2% chlorhexidine (Anabond Asep RC). After master cone selection [Figure 2]D, the canals were dried with absorbent points and obturation was performed using cold lateral compaction of gutta-percha and AH Plus resin sealer (Maillefer Dentsply, Germany) [Figure 2]E and access cavity was sealed using composite restoration (GC Corp, Tokyo, Japan). Patient was asymptomatic on follow up after 6 months. [Figure 2]F.

Case 2

A 38-year-old female patient reported to our outpatient department with a chief complaint of decay in the upper right back tooth. On examination, a class II distoproximal deep caries was found in relation to #14. The tooth was tender on vertical percussion and mobility was within physiological limits. Preoperative radiographic evaluation showed distoproximal radiolucency in relation to #14 approaching the pulp space with widening of periodontal ligament space and loss of lamina dura [Figure 3]. A diagnosis of symptomatic irreversible pulpitis with symptomatic apical periodontitis was made and a nonsurgical root canal treatment was planned for the patient.
Figure 3: Preoperative radiograph

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The tooth was anesthetized using 2% lignocaine containing 1:2,00,000 epinephrine. Under rubber dam isolation, endodontic access cavity preparation was done. Two canals- buccal and palatal were located initially and pulp extirpation done. An intra-canal dressing with calcium hydroxide paste (Calcicur; VOCO,Cuxhaven, Germany) was placed into the canals using a Lentulo Spiral (Dentsply Maillefer). The access cavity was sealed temporarily with cotton pellet and Cavit (3M ESPE AG, Seefeld, Germany).

On second visit, the access cavity was re-entered under local anesthesia and distobuccal canal was located within the buccal canal on exploration. Coronal enlargement was performed with a orifice shaper SX file of protaper system (Dentsply Maillefer, Ballaigues, Switzerland). The working length was determined using an apex locator (Rayapex, Dentsply Maillefer, Ballaigues, Switzerland) and was later confirmed using radiograph [Figure 4]. Multiple working length radiographs were taken at different angulations for further understanding of root canal morphology.
Figure 4: Working length radiograph

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Cleaning and shaping were performed using hand protaper with crown-down technique till F2. Irrigation was performed using normal saline, 2.5% sodium hypochlorite solution (Parcan, Septodont) and 17% EDTA (Md cleanser, Meta biomed) followed by 2% chlorhexidine di-gluconate (Anabond Asep RC) used as the final irrigant. The canals were dried with absorbent points, and obturation was performed using cold lateral compaction of gutta-percha and AH Plus resin sealer (Maillefer Dentsply, Konstanz, Germany) [Figure 5]A. The tooth was then restored with composite resin (GC Corp, Tokyo, Japan). The patient was advised a full-coverage porcelain crown and was asymptomatic during the follow up period of 6 months [Figure 5]B.
Figure 5: Obturation radiograph (A) and radiograph after 6 months (B)

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  Discussion Top

Most common presentation of maxillary first premolars is two roots with two canals. Anatomical variations are often missed when clinicians are not aware about the possible variations in external and internal morphology of teeth. Therefore, meticulous care must be taken from diagnosis till completion of treatment. Periapical radiographs are most common method for assessing the root canal system. Three rooted premolars can sometimes be made out clearly from conventional radiographs, otherwise it cannot be seen and frequently missed. Sieraski et al. in 1985 suggested that during assessment of straight periapical radiographs, when the mesiodistal width of the middle third of root is equal or greater than the mesiodistal width of the crown, it could indicate the possibility of three rooted premolars/three canals.[9] Fast break guideline can be used when sudden narrowing or disappearance of the canal is seen in radiographs which indicates canal division. Tracing of individual root periodontal ligament space can also be helpful in locating additional roots. Multiple preoperative radiographs including straight and angled (15 to 20 degrees mesial or distal) is useful in diagnosing the number of roots and root canals.

With the advances in imaging modality, cone beam computed tomography (CBCT) provides an excellent diagnostic tool for assessing canal variations. However, it could not be used in these cases due to unwillingness of the patients and radiation concerns.

Access cavity outline for a tooth depends upon the location of canal orifices and obtaining straight line access to the root canal. The usual access shape is long oval shape for maxillary first premolar with buccal and palatal canal. With the presence of a third canal orifice, the access outline has to be changed accordingly. Balleri et al. in 1997 suggested a T-shaped access outline for three rooted premolars with three separate canal orifices.[12] The present case report consists of two cases with two canal orifices, buccal and palatal respectively with two canals splitting from the middle third within the buccal canal. Therefore, no access modification was done in these cases.

Use of magnification aids like dental loupes and operating microscope, good illumination is recommended. Use of sharp explorer like DG-16/CK-17, use of ultrasonic tips for troughing grooves, staining with 1% methylene blue dye or ophthalmic dyes, “champagne bubble” test using sodium hypochlorite and visualizing bleeding points are helpful in locating additional canals.[13]

During exploration, sometimes the MB and DB canals may appear closer together or the canals might be splitting within single orifice at middle or apical third. Hence, the clinician must observe for any obstruction or deviation of the files while locating canals and a great amount of tactile feel and precurving of k-files is required.

Maxillary premolar with additional canals can present with technical difficulties during chemomechanical preparation. The canal can be narrow or might have sharp curvature thus increasing the susceptibility for procedural errors like perforation, instrument separation, ledges, canal blockages, transportation. Thus, clinician must take meticulous care and use of small taper, flexible nickel titanium rotary instruments and copious irrigation with sodium hypochlorite followed by EDTA is recommended.

During canal obturation, separate master cones can be used for obturation in case of three visible and separate canal orifices, however clinical skill and care is required during obturation if canals are splitting in middle or apical third. In case of cervical third bi/trifurcation use of warm vertical compaction and in case of thin root canal walls either lateral compaction or single cone obturation can be done. If middle third bi/trifurcation is present, then aid of magnification and illumination is required and if there is difficulty in accommodating multiple master cones, larger master cone should be cut extraorally at the level of bifurcation and a spreader or file can be used to pierce the cut end of the master cone which is inserted into canal and rotated clockwise with apical pressure to loosen the file. Then a plugger can be used to compact the apical gutta percha. A file or paper point must be inserted into the other canal to prevent blockage during obturation. Remaining canal can be obturated using backfilling. In case of apical third bi/trifurcation, use of magnification with aid of operating microscope and good illumination is required. Hermann and Hulsmann suggested “Squirt technique” which can be used to obturate both ends of the root canals simultaneously by injection thermoplasticized gutta percha followed by back filling[14] or else, two or three separate master cones can be used with each cone being sheared apical to the bi- or trifurcation, allowing room for the next master cone to be seated. Once the individual canals in the apical third are filed, the coronal canal is can be backfilled.[15]

According to various studies in literature, variations in maxillary premolar is not a common finding, however clinician should be knowledgeable about the anatomic diversities before endodontically treating any tooth. This case report highlights the importance of diagnosis and exploration during endodontic treatment of maxillary first premolar.

  Conclusion Top

This case report presents endodontic management of two patients with maxillary first premolars having three canals. Presence of additional canal in maxillary premolar can possess challenges during endodontic treatment. Sound knowledge regarding the possible anatomic variations and careful evaluation during radiographic assessment, root canal exploration and obturation must be needed during treatment.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Hoen MM, Pink FE Contemporary endodontic retreatments: An analysis based on clinical treatment findings. J Endod 2002;28:834-6.  Back to cited text no. 1
Vertucci FJ Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol 1984;58:589-99.  Back to cited text no. 2
Pécora JD, Saquy PC, Sousa Neto MD, Woelfel JB Root form and canal anatomy of maxillary first premolars. Braz Dent J 1992;2:87-94.  Back to cited text no. 3
Pineda F, Kuttler Y Mesiodistal and buccolingual roentgenographic investigation of 7,275 root canals. Oral Surg Oral Med Oral Pathol 1972;33:101-10.  Back to cited text no. 4
Dinakar C, Shetty UA, Salian VV, Shetty P Root canal morphology of maxillary first premolars using the clearing technique in a south indian population: An in vitro study. Int J Appl Basic Med Res 2018;8:143-7.  Back to cited text no. 5
Neelakantan P, Subbarao C, Ahuja R, Subbarao CV Root and canal morphology of indian maxillary premolars by a modified root canal staining technique. Odontology 2011;99:18-21.  Back to cited text no. 6
Karunakaran JV, Ganeshamoorthy T, Anbarasi K, Ragavendran N, Karthick AK Maxillary permanent first premolars with three canals: Incidence analysis using cone beam computerized tomographic techniques. J Pharm Bioallied Sci 2019;11: 474-80.  Back to cited text no. 7
Beltes P, Kalaitzoglou ME, Kantilieraki E, Beltes C, Angelopoulos C 3-rooted maxillary first premolars: An ex vivo study of external and internal morphologies. J Endod 2017;43:1267-72.  Back to cited text no. 8
Sieraski SM, Taylor GN, Kohn RA Identification and endodontic management of three-canalled maxillary premolars. J Endod 1989;15:29-32.  Back to cited text no. 9
Maibaum WW Endodontic treatment of a “ridiculous” maxillary premolar: A case report. Gen Dent 1989;37:340-1.  Back to cited text no. 10
Goon WW The “radiculous” maxillary premolar: Recognition, diagnosis, and case report of surgical intervention. Northwest Dent 1993;72:31-3.  Back to cited text no. 11
Balleri P, Gesi A, Ferrari M Primer premolar superior com tres raices. Endod Pr. 1997;3:13-5.  Back to cited text no. 12
Ingle JI, Baumgartner JC Ingle’s Endodontics. Shelton, CT: PMPH-USA; 2008.  Back to cited text no. 13
Hermann HW, Hülsmann M Problems of root canal obturation. Probl Endod Diagn Treat 2009;1:293-333.  Back to cited text no. 14
Albuquerque D, Kottoor J, Hammo M Endodontic and clinical considerations in the management of variable anatomy in mandibular premolars: A literature review. Biomed Res Int 2014;2014:512574.  Back to cited text no. 15


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]

  [Table 1]


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