Journal of Conservative Dentistry
Home About us Editorial Board Instructions Submission Subscribe Advertise Contact e-Alerts Login 
Users Online: 865
Print this page  Email this page Bookmark this page Small font sizeDefault font sizeIncrease font size

CASE REPORT Table of Contents   
Year : 2008  |  Volume : 11  |  Issue : 4  |  Page : 168-170
Endodontic management of a maxillary second premolar with an S-shaped root canal

Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College, Chennai, India

Click here for correspondence address and email

Date of Submission25-Mar-2008
Date of Decision28-Apr-2008
Date of Acceptance26-May-2008


Complex and unusual root canal morphology is an often occurring phenomenon. Understanding the unusual root canal morphology contributes to success in endodontic treatment. One such variant root canal morphology is the 'S' shaped or bayonet shaped root canal. This case report discusses endodontic treatment of a maxillary second premolar with an 'S' shaped root canal.

Keywords: Bayonet shaped canal; double-flare technique; S-shaped canals.

How to cite this article:
Reuben J, Velmurugan N, Vasanthi S, Priya, Vijaylakshmi. Endodontic management of a maxillary second premolar with an S-shaped root canal. J Conserv Dent 2008;11:168-70

How to cite this URL:
Reuben J, Velmurugan N, Vasanthi S, Priya, Vijaylakshmi. Endodontic management of a maxillary second premolar with an S-shaped root canal. J Conserv Dent [serial online] 2008 [cited 2022 Aug 9];11:168-70. Available from:

   Introduction Top

Variations in root canal system occur so often that it is considered a normally occurring phenomenon. Endodontic therapy will be successful only when a thorough disinfection of the entire root canal system is achieved. Understanding these unusual root canal morphology will contribute to success in endodontics.

According to Vertucci, [1],[2],[3] maxillary premolars are the teeth with the maximum anatomic variations. One such variation that occurs often in the maxillary premolars is the 'S' shaped or bayonet shaped root canal. The 'S' shaped root canals have also been reported in maxillary laterals, maxillary canines and mandibular molars.

This report discusses the endodontic management of an 'S' shaped root canal.

   Case report Top

A 34-year-old female patient was referred to the Department of Conservative Dentistry and Endodontics, for the management of a right maxillary second premolar. On clinical examination, tooth 15 had a large carious lesion on the disto-proximal aspect. The patient gave a history of severe pain for the past three days. Radiographic examination of the tooth revealed radiolucency in the disto-proximal aspect, very close to the pulp space. The roots were doubly curved (Bayonet or 'S' shaped). From the clinical and radiographic findings, a diagnosis of irreversible pulpitis was made in relation to 15. Hence, endodontic treatment was initiated in 15.

The right upper maxillary premolar was anaesthetized with 2% lignocaine and access was opened with a No: 2 round bur, under rubber dam isolation [Figure 1]. The completed access preparation was oval in outline, in the bucco-palatal direction.

For determining the patency of the root canals, No:10 SS K-files were used [Figure 2]. The buccal canal was easily negotiated to the apex, as it had only one curvature, towards the distal. The buccal canal was cleaned and shaped using Protaper rotary instruments (Sx (Shaper file x), S1 (shaper 1), S2 (shaper 2)). Saline, NaOCl (Sodium hypochlorite), and EDTA (Ethylene diamine tetra acetic acid) were used as irrigants.

Unlike the buccal root, the palatal root was negotiable only up to the middle third of the root canal. There was resistance to the movement of the patency file. The palatal root canal was enlarged with protaper rotary instruments (Sx) in a crown down motion, right up to the straight portion of the canal. Once this was done, the patency file slid in easily, to the full length. The working length was established using an apex locator (Root ZX, J. Morita, Mfg. Corp, Japan) and confirmed using a radiograph [Figure 3]. The root canal was initially enlarged using NiTi hand files (MANI, Inc, Japan). Three percent NaOCl, EDTA and saline were used as irrigants. The apical portion of the palatal canal was prepared using short amplitude filing. The apical portion and the middle portion were merged using circumferential filing. Both the buccal and palatal canals were obturated using Guttapercha by cold lateral compaction technique [Figure 4].

   Discussion Top

The 'S' shaped canal has two curves, with the apical curve being very difficult to negotiate. The chances of strip perforation are very high in these root canals. (Depending on the degree of the apical curvature, in a few cases it is impossible to instrument this area.) Guttman [4] suggested preflaring the coronal 1/3 rd of the canal (at the expense of the tooth structure) to reduce the angle of curvature. Once this is done, it is easy to negotiate the remainder of the root canal.

In this case, both the canals were not S-shaped. The buccal canal had only a mild distal curvature; hence this canal was prepared in a crown-down technique using protaper rotary instrument.

As the palatal canal was doubly curved, a double flare technique was used to enlarge this canal. The access cavity was flared in the coronal-third, in order to reduce the angle of curvature to the first curve. Reducing the angle of curvature by flaring the access (at the expense of the tooth structure) will make the approach to the second curve much easier. [5] Preflaring, in this case, was done with Sx of the protaper instrument. Once this was done, the palatal canal was negotiable, up to the apex. NiTi hand files, with 0.02 taper, were used to prepare the apical portion of the root canal. Short amplitude filing was done to enlarge the apical portion and also to merge it with coronal-third of the root canal. The apical enlargement was limited to size 25 only. Any over enlargement can easily result in perforation in these canals.

   Conclusion Top

Understanding the complex root canal morphology and choosing a canal preparation technique more suited for such morphology, will contribute to successful endodontic treatment.

   References Top

1.Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral Surg 1974;38:589-99.  Back to cited text no. 1    
2.Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral surg Oral Med Oral Path Oral Radiol Endod 1984;58:589-99.  Back to cited text no. 2    
3.Cohen. Pathways of the pulp. 9 th ed. Missouri: Mosby - Year book Inc; 2002. p. 152.  Back to cited text no. 3    
4.Guttman JL. Problem solving in endodontics. 3 rd ed. Missouri: Mosby -Year book Inc; 1997. p. 116.  Back to cited text no. 4    
5.Weine S. Endodontic therapy. 6 th ed. p. 205.  Back to cited text no. 5    

Correspondence Address:
Joseph Reuben
Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College, Chennai
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0972-0707.48842

Rights and Permissions


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

This article has been cited by
1 Minimally Invasive Endodontic Management of a Maxillary Second Premolar with an S-shaped Root Canal using the Self-adjusting File
Sharad R Kokate, Ajinkya M Pawar, Mansing G Pawar
Journal of Contemporary Dentistry. 2015; 5(1): 35
[Pubmed] | [DOI]
2 Use of Cone-beam Computed Tomography to Evaluate Root Canal Morphology and Locate Root Canal Orifices of Maxillary Second Premolars in a Chinese Subpopulation
Lin Yang,Xinyu Chen,Cheng Tian,Ting Han,Yan Wang
Journal of Endodontics. 2014; 40(5): 630
[Pubmed] | [DOI]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *
* Registration required (free)  

    Case report
    Article Figures

 Article Access Statistics
    PDF Downloaded487    
    Comments [Add]    
    Cited by others 2    

Recommend this journal