Endodontic Techniques and Tips
A leading endodontist shares his keys to successful procedures
Prior to achieving successful endodontic shaping, obtaining proper endodontic access is key. This is accomplished by identifying the location of chamber roof, piercing it, and removing the entire roof without jeopardizing the floor of the pulp chamber, which can lead to a perforation if violated.
Because the pulp chamber lies approximately 6.5 mm in depth away from the height of the cusps of any tooth, access to the pulp chamber can be gained safely without perforating the floor.1-4 Naturally, this rule is most important in multi-rooted teeth with furcations between the roots.
The dentist can take advantage of this fact by creating a depth cut of 7.0 mm with a high-speed, surgical length round bur that will place the cutting tip into the pulp chamber, whether wide open or highly calcified. This approach should not be performed on teeth that have occlusal surfaces with significant attrition.
Once the penetration into the pulp chamber is completed, the same bur can be used to pull up on the walls of the tooth to remove the rest of the roof. Alternatively, a non-end-cutting cylindrical diamond bur can be used to widen the walls laterally at the depth established by the use of the round bur.
The best clue for knowing where to relieve the secondary dentin is the color of the floor. The recessed pulp presents as darkened dentin. The clinician will not find a canal where the dentin is getting lighter. As this darkened dentin is uncovered, you may find that it takes the shape of a “Y” or square configuration in molars, with the canals most likely to be found at the greatest extension of each configuration.
An excellent way to remove the secondary dentin is with a piezo ultrasonic tip.5 The EDS Ultrasonic Kit (Essential Dental Systems, www.edsdental.com) I use also has the benefit of containing a passive ultrasonic irrigation tip for activating solutions in the canal and a post remover tip to quickly and easily break the cementation seal of the post for removal.
After access to the floor of the pulp chamber is gained, the next step is to find the orifices of the canals that are branching from the floor. In maxillary molars, the canal most likely to be missed is MB2. In mandibular molars, practitioners often overlook distolingual and middle mesial canals.
Glide Path Creation
After preparing straight-line access to the canal orifice (Figure 1), use a small SafeSider instrument (Essential Dental Systems) to explore the canal. The first SafeSider that I typically use by hand is a size 08 to determine the working length with the help of an apex locator. I then use the SafeSider in sizes 10, 15, and 20 to verify patency and confirm a smooth, reproducible glide path (Figure 2). I always irrigate and enlarge the glide path to a minimum 20/02 preparation.
In the presence of an irrigant, follow the glide path and shape the wider extensions of oval canals with the Tango-Endo® 30/02 shaping instrument (Essential Dental Systems) (single blue band on the latch head) (Figure 3). Use a gentle inward pecking motion, with short amplitude strokes of 2 to 3 mm until the working length is reached. Clean the flutes frequently during instrumentation and inspect for unwinding or abnormalities. I recommend always utilizing minimal apical pressure and not forcing the instrument down the canal. Using short pecking motions is more effective than pushing the instrument apically.
I then use the Tango-Endo 30/04 finishing instrument (double blue band on the latch head) in the same manner as described above (Figure 4). If you cannot achieve length, repeat the use of the Tango-Endo 30/02 shaping instrument. Confirm the Tango-Endo finishing instrument reaches the apical measurement. Move the instrument continuously against the canal walls until there is no resistance. The precision Tango-Endo gutta percha point is now fit. (Verify the gutta percha point fits to length as shown in Figure 5.)
The Tango-Endo instrumentation system works with any obturation system (ie, vertical, lateral condensation, master point, thermoplastic). Due to its superior apical sealing ability,6 I use it with EZ-Fill® Xpress root canal cement (Essential Dental Systems) and the Bi-Directional spiral (Essential Dental Systems). Figure 6 and Figure 7 demonstrate the preoperative and postoperative clinical radiographs.
The result is a final shape that reflects the original canal anatomy without excessive tooth structure being removed mesiodistally or inadequate removal of tooth structure buccolingually.
Tango-Endo instruments are specifically designed to be used in the Tango-Endo reciprocating handpiece. The handpiece is a 4:1 reduction with a 45º equal arc of reciprocal motion. Because the instruments are designed as modified reamers, they widen or enlarge an existing hole. That is exactly the situation that we encounter in endodontics treatment—widening the existing root canal to clean and shape it.
The Tango-Endo instruments are specifically designed for maximum cutting efficiency and reduced instrument breakage when used in their equally 45º reciprocating motion handpiece. In my opinion, the static 45º motion of this handpiece is preferable compared with the progressive reciprocating movement of other systems. The back-and-forth motion is less prone to instrument separation versus progressive movements that create a complete 360º motion every three to six cycles. The Tango-Endo handpiece also has the added benefit of fitting on an E-Type attachment. It can fit on any E-Type electric motor or airline. Therefore, the dentist does not have to purchase expensive equipment to begin.
5 Tips for Successful Endodontics
In summary, my extensive experience in endodontics has helped me develop the following five tips that can help ensure predictable and successful endodontic procedures.
1. Always irrigate well during instrumentation. Irrigating not only aids in removing bacteria and debris from the canal, it also helps in lubricating and facilitating canal instrumentation.
2. Wipe the instrument during instrumentation. By wiping the instrument, you remove debris from the flutes and facilitate efficient and safe instrumentation.
3. Use a short pecking motion. By using a short 2- to 3-mm pecking motion, you move debris up, which helps not impact debris apically.
4. Make sure the instrument fits loosely in the canal. After you have achieved the working length, work the lateral walls, instrumenting until it is loose and patent in the canal before moving to the next instrument in sequence.
5. Use the correct handpiece. For example, use only Tango-Endo instruments in the Tango-Endo handpiece. Other handpieces may cause instrument separation.
Allan S. Deutsch, DMD, is the executive vice president, co-director of dental research, and co-founder of Essential Dental Systems.
About the Author
Allan S. Deutsch, DMD
Assistant Clinical Professorof Endodontics
Columbia School of Dental Medicine
New York, New York
For more information, contact:
Essential Dental Systems
1. Deutsch AS, Musikant BL. Morphological measurements of anatomic landmarks in human maxillary and mandibular molar pulp chambers. J Endod. 2004;30(6):388-390.
2. Deutsch AS, Musikant BL, Gu S, Isidro M. Morphological measurements of anatomic landmarks in pulp chambers of human maxillary furcated bicuspids. J Endod. 2005;31(8):570-573.
3. Lee MM, Rasimick BJ, Turner AM, et al. Morphological measurements of anatomic landmarks in pulp chambers of human anterior teeth. J Endod. 2007;33(2):129-131.
4. Azim AA, Azim KA, Deutsch AS, Huang GT.. Acquisition of anatomic parameters concerning molar pulp chamber landmarks using cone-beam computed tomography. J Endod. 2014;40(9):1298-1302.
5. Wan J, Deutsch AS, Musikant BL, Guzman J.. Evaluation of the breakage of orthograde endodontic ultrasonic tips. J Endod. 2014;40(12):2074-2076.
6. Cohen BI, Pagnillo MK, Musikant BL, Deutsch AS. The evaluation of apical leakage for three endodontic fill systems. Gen Dent. 1998;46(6):618-623.