Are we clean yet? A look at endodontic instrumentation

As a clinician, you may ask if one endodontic instrument can do the work of an entire series of instruments. Dr. Diwakar Kinra, editor of DE’s ENDO File, takes a look at endodontic instrumentation and shares his advice.


When implementing WaveOne (DENTSPLY Tulsa Dental Specialties) into patient care, the practitioner may ask if one endodontic instrument can do the work of an entire series of instruments. We must remember that instruments shape while irrigants clean. It has been demonstrated that all instruments leave 35% of the canal wall untouched during shaping. (1) Therefore, irrigation is truly the only method to clean the entire canal.

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With full-strength sodium hypochlorite and QMix (DENTSPLY Tulsa Dental Specialties), the canal can be thoroughly cleaned and disinfected. (2) For this to be successful, the irrigating needle needs to be within 2 mm of the apex. As seen in Fig. 1, the WaveOne primary file allows for a 27-gauge NiTi needle to accomplish this task. Carson and Baumgartner stated that instrumented surfaces are more difficult to clean than uninstrumented surfaces. (3) Therefore, overenlarging the canal to ensure cleanliness is not necessary and may be detrimental to the structural integrity of the tooth. This supports the principle of Schilder that small apical sizes allow for properly prepared cases. (4)


Fig. 1

Click here to see chart larger.


1. Peters OA, Schönenberger K, Laib A. Effects of four Ni-Ti preparation techniques on root canal geometry assessed by micro-computed tomography. Int Endod J. 2001 Apr;34(3):221-230.

2. Dai L, Khechen K, Khan S, Gillen B, Loushine BA, Wimmer CE, Gutmann JL, Pashley D, Tay FR. The effect of QMix, an experimental antibacterial root canal irrigant, on removal of canal wall smear layer and debris. J Endod. 2011 Jan;37(1):80-84.

3. Carson ML, Baumgartner JC, Peters DD. Scanning electron microscopic investigation of the smeared layer on root canal walls. J Endod. 1984 Oct;10(10):477-483.

4. Schilder H. Cleaning and shaping the root canal. Dent Clin North Am. 1974 Apr; 18(2):269-296.

Diwakarkinra Diwakar Kinra, DDS, MS, is the editor of DE’s ENDO File. He received his dental degree in 1999 from the University of Michigan and his master’s degree in endodontics at the University of Detroit-Mercy in 2004. Afterwards, he began his solo private practice limited to endodontics in Flint, Mich. He has lectured domestically and internationally on practice management and endodontics since 2007. For further information, please contact Dr. Kinra at

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