|Year : 2017 | Volume
| Issue : 2 | Page : 160-163
Negotiating the bends: An endodontic management of curved canals – A case series
Mithra Nidarsh Hegde, Anish Kumar Lagisetti, Manjiri N Honap
Department of Conservative Dentistry and Endodontics, A. B. Shetty Memorial Institute of Dental Sciences, Mangalore, Karnataka, India
|Date of Web Publication||6-Nov-2017|
Anish Kumar Lagisetti
Department of Conservative Dentistry and Endodontics, A. B. Shetty Memorial Institute of Dental Sciences, Deralakatte, Mangalore - 575 018, Karnataka
Source of Support: None, Conflict of Interest: None
Negotiating the dilacerated and S-shaped roots often present a challenging situation in their Endodontic treatment. An insight of canal anatomy, coronal preflaring, precurving of all the hand instruments and use of smaller number files facilitates easy negotiation of canal curvature and maintenance of the shape without any procedural mishaps. All hand files are used in present cases with balanced force technique which has advantages of less extrusion of debris, less iatrogenic errors, and maintenance of instrument centrally. A thorough assessment of preoperative radiographs coupled with careful approach yielded into a safe and a successful endodontic treatment of such teeth. This case series presents two such interesting cases of endodontic management of curved canals.
Keywords: Curved canal, dilaceration, S-shaped canal
|How to cite this article:|
Hegde MN, Lagisetti AK, Honap MN. Negotiating the bends: An endodontic management of curved canals – A case series. Endodontology 2017;29:160-3
| Introduction|| |
A straight root with a straight canal is rather an exception than a common finding. The dilaceration or curvature in the root is considered to be a developmental anomaly in which there is an abrupt change in axial inclination between the root and the crown. Negotiating such curvatures often present a challenging situation in endodontic treatment.
The common causes of endodontic treatment failure in such cases of atypical canal anatomies are due to procedural errors such as ledge formation, fractured instruments, blockage of the canal, zipping, or elbow creation. A thorough assessment of the preoperative radiographs, careful and a meticulous approach can yield into a safe and a successful endodontic treatment of such teeth. The current case series presents two such interesting cases of endodontic management of dilacerated mandibular molar and bayonet shaped root canal in maxillary premolar.
| Case Reports|| |
A 21-year-old male patient reported to the outpatient Department of conservative dentistry and endodontics with the chief complaint of pain in relation to lower right back tooth region.
Clinical examination revealed mandibular right first molar having amalgam restoration. The tooth was tender on percussion. Medical history was noncontributory. Tooth was vital when pulp sensibility tests (electric pulp test and heat test) were conducted. The radiographic examination revealed the amalgam restoration involving both mesial and distal pulp horn, with periodontal ligament widening. Apart from these findings, a sharp curvature in the mid-third region of the tooth was observed on the radiograph [Figure 1]a. A diagnosis of chronic irreversible pulpitis was established and the endodontic treatment was planned followed by full coverage restoration of the tooth.
|Figure 1: Steps in management of dilacerated mandibular molar (tooth number 46) (a) Preoperative radiograph (b) working length determination (c) Master cone selection (d) obturation (e) follow up radiograph after 6 months|
Click here to view
With informed consent, local anesthesia was administered using 2% lignocaine and 1:200,000 Adrenaline and Endodontic therapy was initiated under rubber dam isolation. Amalgam restoration was removed and the endodontic access cavity was prepared using Endo access bur # 2 (Dentsply Maillefer). All canal orifices are preflared with GG drills size 3.
The pulp chamber was irrigated by following standardized irrigation regimen using 3% of sodium hypochlorite, 17% ethylene diamine tetraacetic acid and physiological saline.
The initial instrumentation was done using pathfinder stainless steel file (SybronEndo, Orange, CA, USA). Working length was determined by electronic apex locator and confirmed by radiograph [Figure 1]b. Glide path was established up to the radiographic working length. The canals were enlarged with subsequent instrumentation done by using #15, #20, #25 K files (Mani, Inc, Japan). For verifying the patency of the root canals, no. 8 and 10 stainless steel K-files (Mani, Inc., Japan) were used.
The apical portions of the canals were prepared using short amplitude filing. Special attention was given on frequent irrigation of the root canal and recapitulation was done to avoid blockage by dentinal debris and to remove the necrotic remnants of the pulp tissue.
Final cleaning and shaping was carried out using Hyflex CM rotary files (Coltene-Whaledent, Switzerland) up to 4% 25 size of the instrument. Calcium hydroxide was used as an intracanal medicament and closed dressing was given for 2 weeks. In the second visit, the canals were irrigated with saline and dried with paper points.
A master cone radiograph was taken with 25 size 4% Gutta percha [Figure 1]c. The cold lateral condensation method of obturation was performed using calcium hydroxide based sealer [Figure 1]d. The access restoration was done with composite resin to maintain a good coronal seal [Figure 1]e.
The patient was given postoperative instructions and recalled for further follow up. At 6 months recall and follow up, the patient was absolutely asymptomatic and there was no radiographic sign of any periapical disease.
A 19-year-old female patient reported to the outpatient department of conservative dentistry and endodontics, with the chief complaint of pain in relation to upper left back tooth region.
Clinical examination revealed deep caries in relation to disto-occlusal aspect of maxillary left first premolar (tooth-24). The tooth was mildly tender on percussion. Medical history was noncontributory. Tooth was vital when pulp sensibility tests (Electric pulp test and heat test) were conducted. The radiographic examination revealed deep caries in close approximation to pulp with respect to 24, with no signs of periapical pathosis. Apart from these findings, the tooth showed curved (Bayonet or S-shaped) roots [Figure 2]A.
|Figure 2: An endodontic management of bayonet shaped maxillary first premolar (tooth no-24) (A) Preoperative radiograph (B) Radiographic estimation of working length (C) selection of master cone (D) Obturation|
Click here to view
A treatment of deep caries management was planned for the same. The procedure was explained to the patient. Under rubber dam isolation caries were excavated. During excavation pulp was exposed at carious site; hence, pulp space therapy was initiated after obtaining patients consent for the same.
All the initial steps are same as discussed in the first case. Working length was determined by electronic apex locator and confirmed by radiograph [Figure 2]B. All the hand files were introduced with balanced force technique which maintains the instrument centrally in the canal. Special attention was given on frequent irrigation of the root canal and recapitulation. Final cleaning and shaping were carried out using Neoniti A1rotary files single instrument based technique, (Neolix sas, Châtres-La-Forêt, France) up to 6% 25 size of the instrument. Calcium hydroxide was used as an intracanal medicament and closed dressing was given for 12 days. In the second visit, the canals were irrigated and obturated using 25 size 6% Gutta percha [Figure 2]C. The postendodontic restoration was done with composite resin [Figure 2]D. At 3 months recall and follow up, the patient was absolutely asymptomatic and there was no radiographic sign of any periapical disease.
| Discussion|| |
Successful endodontic treatment involves thorough cleaning and shaping of the canals, most of the canals have multiple curvatures along their length, which pose difficulty in root canal instrumentation. Canal curvature can be a dilacerated canal, S-shaped canal, gradual curvature of the root, and sharp curvature in the apical third.
Dilaceration was termed by Tomes and defined as a deviation in the linear relationship of a crown of a tooth to its root. The etiology of dilacerations are trauma to permanent tooth bud or idiopathic developmental disturbance. Vertucci showed various anatomical variations in maxillary premolars and one such variation is S-shaped canal. The present case series included endodontic management of a severely dilacerated molar and S-shaped root canal of a maxillary premolar.
Knowledge of internal root anatomy guides a successful endodontic therapy. In the present case series, proper attention was directed in preoperative radiographic assessment which helped in negotiating root curvature and canal configuration.
The common causes of endodontic treatment failure in cases of atypical canal anatomies are due to procedural errors such as ledge formation, fractured instruments, blockage of canal, zipping, or elbow creation.
According to Gutmann coronal preflaring helps in easy negotiation of the entire curved canal. In the present series of cases, this step was followed. Pathfinder files are unique alternative to no. 6 and no. 8 K files. These files have reduced taper which helps in negotiating the smaller and difficult canals easily with additional benefit of rigidity and enhanced flexibility during canal negotiation. In this case, size K2 25 mm length pathfinder file was used which is approximate size of no. 9 with 1% taper.
Precurving of all the hand instruments and use of smaller number files facilitates easy negotiation of canal curvature  and maintenance of the shape without any procedural mishaps.
All hand files are used with balanced force technique which has advantages of less extrusion of debris, less iatrogenic errors and maintenance of instrument centrally. Usage of rotary files in crown down technique helps in early flaring of coronal third and has advantages such as reduced coronal binding of the instruments, less apical extrusion of debris, and effective irrigation of apical third of the root canal.
| Conclusion|| |
A sound knowledge about internal anatomy of the tooth, thorough assessment of preoperative radiographs is crucial prerequisite in managing bends.
To address challenging mid root curvatures, it is essential to remain patient, first negotiate canals by hand and consider using rotary files in a crown down manner with copious irrigation between each file.
Meticulously followed conventional protocol helped to achieve safe and successful treatment of curved canals. A careful conventional approach resulted in sufficient enlargement of the curved canals, leading to successful treatment.
Appropriate instrumentation techniques and customized treatment planning will help manage curved canals, prevent complications, and enhance the quality of the treatment.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Jafarzadeh H, Abbott PV. Dilaceration: Review of an endodontic challenge. J Endod 2007;33:1025-30.
Sakkir N, Thaha KA, Nair MG, Joseph S, Christalin R. Management of dilacerated and S-shaped root canals – An endodontist's challenge. J Clin Diagn Res 2014;8:ZD22-4.
Hargreaves KM, Berman LH. Cohen's pathways of the pulp. South east Asia edition. Elsevier Health Sciences; 2015.
Ansari I, Maria R. Managing curved canals. Contemp Clin Dent 2012;3:237-41.
] [Full text]
Vertucci FJ. Root canal morphology and its relationship to endodontic procedures. Endodontic topics 2005;10:3-29.
Fava LR. Root canal treatment in an unusual maxillary first molar: A case report. Int Endod J 2001;34:649-53.
Jain N, Tushar S. Curved canals: Ancestral files revisited. Indian J Dent Res 2008;19:267-71.
] [Full text]
Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol 1984;58:589-99.
Roane JB, Sabala CL, Duncanson MG Jr. The “balanced force” concept for instrumentation of curved canals. J Endod 1985;11:203-11.
Elizabeth M. Hand instrumentation in root canal preparation. Endod Topics 2005;10:163-7.
Riitano F. Anatomic endodontic technology (AET) – A crown-down root canal preparation technique: Basic concepts, operative procedure and instruments. Int Endod J 2005;38:575-87.
Bergmans L, Van Cleynenbreugel J, Wevers M, Lambrechts P. Mechanical root canal preparation with NiTi rotary instruments: rationale, performance and safety. Am J Dent 2001;14:324-3.
[Figure 1], [Figure 2]