Which rotary endodontic and obturation system is the best?

This question was submitted by a general dentist: Which rotary endodontic and obturation system is the best?

Dr. Rodrigo Cunha, Assistant Professor and Division Head, Endodontology Program Director in the faculty of Dentistry at the University of Manitoba provided this initial answer.

Currently, there are several rotary endodontic systems in the dental market and all designed with one specific goal in mind – to clean and shape the canal(s). However, several research studies have illustrated that regardless of the type of file used to shape the canal, none are able to contact all the canal walls or surfaces. (1, 2)

Files are generally categorized as:

• Radial-ended files
  • Enable cleaning and shaping but the procedure is slower and safer
  • Examples include: Profile & K3

• Non-radial-ended files
  • Cut more effectively but can also lead to errors if not properly managed
  • Examples include: ProTaper, Twisted Files, Endosequence

The most important factor when choosing and utilizing a particular file system is to follow the appropriate technique outlined by the manufacturer and dictated by the design of the file to remove vital or necrotic tissues from the canal spaces. This will optimize the files’ efficiency and minimize damage to the canal and tooth.

Each file system has advantages and disadvantages; the best system is the one you are proficient with and used to handling.

Additionally, clinicians must adhere to the principles of endodontic treatment: 

• Completely remove infected material from the canal space
• Ensure there is a glide-path before using rotary files
• Preserve tooth structure while reducing the risk of vertical root fracture in the future
• Manage the apical preparation of the canal to avoid transportation or unnecessary enlargement
• Carefully clean and shape the canals in furcation areas to decrease furcation involvement

With respect to obturation, there are 3 techniques that are employed.

1. Warm Vertical Condensation

This is the most commonly used technique in North America. Nowadays, there are several techniques which originated from the classic Schilder’s technique. (3) This technique requires clinicians to use a heat carrier (e.g. Touch n’ heat; Calamus Duo; Elements, Super Endo α²) as well as injectable gutta-percha (e.g. Obtura II, Calamus, Super Endo β)

2. Carrier-based techniques

This is a popular option used to fill canal spaces. Different carrier-based systems use different core materials to deliver gutta-percha to the canals.  Currently, carriers made of cross-linked gutta-percha such as Gutta-Core (Tulsa/Dentsply) are available which may be easier to remove from the canal in situations where retreatment is necessary.

3. Lateral condensation

In this technique, gutta-percha cones are placed within the canal and finger spreaders are used to place filling material and pack the canal space. There is an increased possibility of vertical root fracture using this procedure if excessive pressure is applied against the canal walls. (4)

At this time, there is no scientific evidence to suggest whether one system is more advantageous over another. (5)

References

1. Gergi R, Osta N, Bourbouze G, Zgheib C, Arbab-Chirani R, Naaman A. Effects of three nickel titanium instrument systems on root canal geometry assessed by micro-computed tomography. Int Endod J. 2014 Apr 9 [Epub ahead of print]
2. Paqué F, Peters OA. Micro-computed tomography evaluation of the preparation of long oval root canals in mandibular molars with the self-adjusting file. J Endod. 2011 Apr;37(4):517-21.
3. Schilder H. Filling root canals in three dimensions. Dent Clin North Am. 1967 Nov:723-44.
4. Murgel CA, Walton RE. Vertical root fracture and dentin deformation in curved roots: the influence of spreader design. Endod Dent Traumatol. 1990 Dec;6(6):273-8.
5. Peng L, Ye L, Tan H, Zhou X. Outcome of root canal obturation by warm gutta-percha versus cold lateral condensation: a meta-analysis. J Endod. 2007 Feb;33(2):106-9.