* denotes required field

Your Name: *



Gender: *

Personal Email: *

This will be your username

Password: *

Display Name: *

This will be what others see in social areas of the site.

Address: *










Phone Number:

School/University: *

Graduation Date: *

Date of Birth: *

ASDA Membership No:





Hi returning User! please login with Facebook credentials where Facebook Username is same as THENEXTDDS Username.




Comments (0)

Crown-Down Preparation: Gradual Tapering of the Root Canal

Learning Objectives:

Upon watching this video, the viewer should:

  • Understand the basics of the “crown-down” style technique
  • Know how to begin the process of remodeling the inner canal of the tooth

The primary goal of the crown-down preparation technique is to produce a gradually tapering shape in the bulk of the root canal system, with the narrowest diameter apically and the greatest diameter coronally. There should be a smooth flow between the two coronal and apical sections. The preparation in the apical 1/3 should be at least at a size 30 to allow good irrigant penetration and facilitate obturation.

Following hand instrumentation, nickel-titanium instruments are rotated at 150 to 350 rpm in a speed-reduction handpiece using an electric torque-controlled motor. Instruments should be used sequentially in a crown down manner. This will facilitate obturation. During mechanical preparation the canal is repeatedly irrigated with sodium hypochlorite solution.

Related Reading:

  1. Brown P, Herbranson E, eds. Dental anatomy & 3D interactive tooth atlas Version 2.0. Carol Stream, IL: Quintessence Publishing, 2005.
  2. Vertucci FJ, Haddix JE, Britto LR. Tooth morphology and access cavity preparation. In: Cohen S, Hargeaves KM, eds. Pathways of the Pulp, 9th ed. Philadelphia, PA: Mosby, 2005.
  3. Carrotte P. Endodontics: Part 6. Rubber dam and access cavities. Brit Dent J 2004;197(9):527-534.
  4. Salehrabi R, Rotstein I.  Endodontic treatment outcomes in a large patient population in the USA: An epidemiological study.  J Endod 2004;30(12):846-850. 
  5. Hess W.  The Anatomy of the Root Canals of the Teeth of the Permanent Dentition. London England: J. Bale, Sons & Danielsson, Ltd.; 1925. 
  6. Wolcott J, Ishley D, Kennedy W, et al.  A 5 yr clinical investigation of second mesiobuccal canals in endodontically treated and retreated maxillary molars.  J Endod 2005;31(4):262-264. 
  7. Buhrley LJ, Barrows MJ, BeGole EA, Wenckus CS.  Effect of magnification on locating the MB2 canal in maxillary molars.  J Endod 2002;28(4):324-327. 
  8. Stropko JJ.  Canal morphology of maxillary molars: Clinical observations of canal configurations.  J Endod 1999;25(6):446-450. 
  9. Weine FS. Endodontic Therapy.  4th ed. St. Louis, MO: Mosby; 1989:222-223. 
  10. Kulild JC, Peters DD.  Incidence and configuration of canal systems in the mesiobuccal root of maxillary first and second molars.  J Endod 1990;16(7):311-317. 
  11. Gilles J, Reader A.  An SEM investigation of the mesiolingual canal in human maxillary first and second molars.  Oral Surg Oral Med Oral Pathol 1990;70(5):638-643. 
  12. Jung IY, Seo MA, Fouad AF, et al.  Apical anatomy in mesial and mesiobuccal roots of permanent first molars. J Endod 2005;31(5):364-368. 
Sorry, your current access level does not permit you to view this page.