Abstract
The success of non-surgical endodontic root canal treatment requires the use of files and instruments to remove necrotic and infected tissues. The cleaning and shaping are separate concepts but are always performed together. The goal of cleaning the root canal is the removal of necrotic pulp and infected tissues. The goal of shaping the canal is to maintain the apical foramen as small as possible in its original anatomic position. A good endodontic treatment outcome is dependent on the removal of necrotic pulp and infected tissues to a low level that cannot cause a flare up which will require retreatment. After a straight-line access cavity has been cut to allow direct access of the instruments into the root canals, and the orifices of the root canals have been identified. The next step is to instrument the root canals. The instrumentation process can be simplified by dividing the procedure in a series of steps. The majority of teeth are approximately 19-25 mm in length. Most roots are 9-15mm and most crowns are 10mm in length. An easy concept is to divide the root canal into three regions; coronal, middle and apical. Each of these regions is likely to be between 3-5mm in length. Dividing the root canal into three regions is a helpful strategy for instrumenting complicated calcified root canals with a challenging morphology. It is necessary to accurately measure tooth length in order to carry out and fulfill the basic tenets of root canal therapy. This measurement should be 0.5mm to 1mm short of the radiographic apical foramen, to create an apical stop within the tooth structure in order to confine instrumentation and the filling material. The radiograhic length is the length of the tooth as it appears on the radiograph. The estimated working length is the radiographic length minus 1mm. The final working length is -1mm substracted from the anatomical apex measure from the working length radiograph. NiTi rotary instruments have proved to be extremely successful for cleaning and shaping root canals, but they should not be used when the dentinal walls are extremely thin to avoid perforation of the root canal. Curved canals are the most challenging to instrument, because the distortion of the files and instruments will cut into the curve to reduce its angle, and place pressure on the cutting tips in an opposite direction, thereby increasing the risk of cutting a perforation. The risk of cutting a perforation in curved canals increases when larger file sizes are used. To avoid perforations, the concept of anti-curvature filing is to prepare a straight line access through the root canal to the apical region, by filing away the bulky root structure to create a displacement space, and by not touching the thin root walls which are in danger of being perforated. When a perforation occurs, it should be repaired immediately using restorative materials, with a thin liner of MTA being placed against the vital periodontal tissues or bone. The prognosis of a perforated tooth depends on the size, location, and the time taken to repair it.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Bibliography
Schilder H. Cleaning and shaping the root canal. Dent Clin North Am. 1974;18:269–96.
Sabala CL, Biggs JT. A standard predetermined endodontic preparation concept. Compendium. 1991;12:656, 658, 660.
Alves Vde O. Endodontic flare-ups: a prospective study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010;110(5):e68–72.
Akbar I, Iqbal A, Al-Omiri MK. Flare-up rate in molars with periapical radiolucency in one-visit vs two-visit endodontic treatment. J Contemp Dent Pract. 2013;14:414–8.
Nobuhara WK, del Rio CE. Incidence of periradicular pathoses in endodontic treatment failures. J Endod. 1993;19:315–8.
Siqueira Jr JF. Microbial causes of endodontic flare-ups. Int Endod J. 2003;36(7):453–63.
de Pablo OV, Estevez R, Heilborn C, Cohenca N. Root anatomy and canal configuration of the permanent mandibular first molar: clinical implications and recommendations. Quintessence Int. 2012;43:15–27.
Paqué F, Balmer M, Attin T, Peters OA. Preparation of oval-shaped root canals in mandibular molars using nickel-titanium rotary instruments: a micro-computed tomography study. J Endod. 2010;36:703–7.
Pujar M, Bhagwat SV. Determination of the morphological irregularities in the middle and apical 1/3rd region of the root canal system of permanent maxillary incisors. Indian J Dent Res. 2002;13:96–8.
Ruddle CJ. Current concepts for preparing the root canal system. Dent Today. 2001;20:76–83.
American Association of Endodontists, Colleages for Excellence, Rotary instrumentation: an endodontic perspective. American Association of Endodontists; 2008.
Haapasalo M, Shen Y, Wang Z, Gao Y. Irrigation in endodontics. Br Dent J. 2014;216:299–303.
Zhu WC, Gyamfi J, Niu LN, Schoeffel GJ, Liu SY, Santarcangelo F, Khan S, Tay KC, Pashley DH, Tay FR. Anatomy of sodium hypochlorite accidents involving facial ecchymosis – a review. J Dent. 2013;41:935–48.
Buchanan LS. The standardized-taper root canal preparation–part 6. GT file technique in abruptly curved canals. Int Endod J. 2001;34:250–9.
Ricucci D. Apical limit of root canal instrumentation and obturation, part 1. Literature review. Int Endod J. 1998;31:384–93.
Grove CJ. A new simple standardized technique producing perfect fitting impermeable root canal filings extended to the dentinocemento junction. Dent Items Interest. 1928;50:855–7.
Siqueira J, Rôças I. Clinical implications and microbiology of bacterial persistence after treatment procedures. J Endod. 2008;34:1291–301.
Yusuf H. The significance of the presence of foreign material periapically as a cause of failure of root treatment. Oral Surg Oral Med Oral Pathol. 1982;54:566–74.
Georgopoulou M, Anastassiadis P, Sykaras S. Pain after chemomechanical preparation. Int Endod J. 1986;19:309–14.
Sjögren U, Hagglund B, Sundqvist G, Wing K. Factors affecting the long-term results of endodontic treatment. J Endod. 1990;16:498–504.
Ng Y-L, Mann V, Rahbaran S, Lewsey J, Gulabivala K. Outcome of primary root canal treatment: systematic review of the literature – part 2. Influence of clinical factors. Int Endod J. 2008;41:6–31.
Ricucci D, Langeland K. Apical limit of root canal instrumentation and obturation. Part 2. A histological study. Int Endod J. 1998;31:394–409.
European Society of Endodontology. Quality guidelines for endodontic treatment: consensus report of the European Society of Endodontology. Int Endod J. 2006;39:921–30.
Melius B, Jiang J, Zhu Q. Measurement of the distance between the minor foramen and the anatomic apex by digital and conventional radiography. J Endod. 2002;28:125–6.
Ravanshad S, Adl A, Anvar J. Effect of working length measurement by electronic apex locator or radiography on the adequacy of final working length: a randomized clinical trial. J Endod. 2010;36:1753–6.
Meares WA, Steiman HR. The influence of sodium hypochlorite irrigation on the accuracy of the Root ZX electronic apex locator. J Endod. 2002;28:595–8.
Fan W, Fan B, Gutmann JL, Bian Z, Fan MW. Evaluation of the accuracy of three electronic apex locators using glass tubules. Int Endod J. 2006;39:127–35.
Özsezer E, İnan U, Aydin U. In vivo evaluation of ProPex electronic apex locator. J Endod. 2007;33:974–7.
Malterud M. Minimally invasive biomimetic endodontics: the future is here. Gen Dent. 2013;61:8–10.
Kim HC, Sung SY, Ha JH, Solomonov M, Lee JM, Lee CJ, Kim BM. Stress generation during self-adjusting file movement: minimally invasive instrumentation. J Endod. 2013;39:1572–5.
Cleghorn BM, Christie WH, Dong CC. The root and root canal morphology of the human mandibular second premolar: a literature review. J Endod. 2007;33:1031–7.
Musikant BL, Cohen BI, Deutsch AS. The evolution of instrumentation and obturation leading to a simplified approach. Compend Contin Educ Dent. 2000;21:980–6, 988, 990.
Nielsen BA, Baumgartner JC. Spreader penetration during lateral compaction of resilon and gutta-percha. J Endod. 2006;32:52–4.
Pérez Heredia M, Clavero González J, Ferrer Luque CM, González RodrÃguez MP. Apical seal comparison of low-temperature thermoplasticized gutta-percha technique and lateral condensation with two different master cones. Med Oral Patol Oral Cir Bucal. 2007;12:E175–9.
Diemer F, Sinan A, Calas P. Penetration depth of warm vertical Gutta-Percha pluggers: impact of apical preparation. J Endod. 2006;32:123–6.
Testori T, Badino M, Castagnola M. Vertical root fractures in endodontically treated teeth: a clinical survey of 36 cases. J Endod. 1993;19:87–91.
Ivanovic V, Beljic-Ivanovic K. Determining working length or how to locate the apical terminus (part I). Roots. 2009;4:30–6.
Aziz A, Chandler NP, Hauman CH, Leichter JW, McNaughton A, Tompkins GR. Infection of apical dentin and root-end cavity disinfection. J Endod. 2012;38:1387–90.
Eldeeb ME, Boraas JC. The effect of different files on the preparation shape of severely curved canals. Int Endod J. 1985;18:1–7.
Chow TW. Mechanical effectiveness of root canal irrigation. J Endod. 1983;9:475–9.
Card SJ, Sigurdsson A, Orstavik D, Trope M. The effectiveness of increased apical enlargement in reducing intracanal bacteria. J Endod. 2002;28:779–83.
American National Standards Institute/American Dental Association Standard No. 28—root canal files and reamers, type, Chicago, 2008.
Tarniţă D, Tarniţă DN, Bîzdoacă N, Mîndrilă I, Vasilescu M. Properties and medical applications of shape memory alloys. Rom J Morphol Embryol. 2009;50:15–21.
Serene TP, Adams JD, Saxena A. Nickel-titanium instruments: applications in endodontics. St. Louis: Ishiaku EuroAmerica; 1995.
Schäfer E, Bürklein S. Impact of nickel-titanium instrumentation of the root canal on clinical outcomes: a focused review. Odontology. 2012;100:130–6.
Saunders EM, Saunders WP. The challenge of preparing the curved root canal. Dent Update. 1997;24(241–4):246–7.
Ricucci D, Siqueira Jr JF. Recurrent apical periodontitis and late endodontic treatment failure related to coronal leakage: a case report. J Endod. 2011;37:1171–5.
Carrotte P. Endodontics: part 8. Filling the root canal system. Br Dent J. 2004;197:667–72.
Waltimo T, Trope M, Haapasalo M, Ørstavik D. Clinical efficacy of treatment procedures in endodontic infection control and one year follow-up of periapical healing. J Endod. 2005;31:863–6.
Heling I, Gorfil C, Slutzky H, Kopolovic K, Zalkind M, Slutzky-Goldberg I. Endodontic failure caused by inadequate restorative procedures: review and treatment recommendations. J Prosthet Dent. 2002;87:674–8.
Tidmarsh BG. Accidental perforation of the roots of teeth. J Oral Rehabil. 1979;6:235–40.
Abou-Rass M, Jann JM, Jobe D, Tsutsui F. Preparation of space for posting: effect on thickness of canal walls and incidence of perforation in molars. J Am Dent Assoc. 1982;104:834–7.
Sinai IH. Endodontic perforations: their prognosis and treatment. J Am Dent Assoc. 1977;95:90–5.
Main C, Mirzayan N, Shabahang S, Torabinejad M. Repair of root perforations using mineral trioxide aggregate: a long-term study. J Endod. 2004;30:80–3.
Bryan EB, Woollard G, Mitchell WC. Nonsurgical repair of furcal perforations: a literature review. Gen Dent. 1999;47:274–8.
Roda RS. Root perforation repair: surgical and nonsurgical management. Pract Proced Aesthet Dent. 2001;13:467–72.
Aggarwal V, Singla M, Miglani S, Kohli S. Comparative evaluation of push-out bond strength of ProRoot MTA, Biodentine, and MTA Plus in furcation perforation repair. J Conserv Dent. 2013;16:462–5.
Aminov L, Moscalu M, Melian A, Salceanu M, Hamburda T, Vataman M. Clinical-radiological study on the role of biostimulating materials in iatrogenic furcation lesions. Rev Med Chir Soc Med Nat Iasi. 2012;116:907–13.
Tavassoli-Hojjati S, Kameli S, Rahimian-Emam S, Ahmadyar M, Asgary S. Calcium enriched mixture cement for primary molars exhibiting root perforations and extensive root resorption: report of three cases. Pediatr Dent. 2014;36:23–7.
Hartwell GR, England MC. Healing of furcation perforations in primate teeth after repair with decalcified freeze-dried bone: a longitudinal study. J Endod. 1993;19:357–61.
Al-Sabek F, Shostad S, Kirkwood KL. Preferential attachment of human gingival fibroblasts to the resin ionomer Geristore. J Endod. 2005;31:205–8.
Karunakaran JV, Kumar SS, Kumar M, Chandrasekhar S, Namitha D. The effects of various irrigating solutions on intra-radicular dentinal surface: an SEM analysis. J Pharm Bioallied Sci. 2012;4 Suppl 2:S125–30.
Author information
Authors and Affiliations
Rights and permissions
Copyright information
© 2015 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Murray, P. (2015). Instrumentation (Techniques, File Systems, File Types, and Techniques). In: A Concise Guide to Endodontic Procedures. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-43730-8_6
Download citation
DOI: https://doi.org/10.1007/978-3-662-43730-8_6
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-662-43729-2
Online ISBN: 978-3-662-43730-8
eBook Packages: MedicineMedicine (R0)