Parameters Worth Discussing Regarding Effective Endodontic Instrumentation

. Safety of the instruments including their ability to stay intact while causing no damage to the teeth being treated such as ledging, producing dentinal micro-cracks, impacting debris, removing excess tooth structure.

. Thoroughness of debridement

. Accuracy of debridement-minimizing distortions

. Detailed assessment of the instruments’ impact on the canal walls

. Potential for apical extrusion of debris

. Potential for apical damage

. Cost

. Reusability

. Adaptability to the wide range of pulpal configuration

. Detailed assessment of the instruments’ potential to impact debris with loss of length

. Efficiency, effectiveness and safety of different engine-driven instrumentation systems

Instruments generally available for canal preparation:

. Stainless steel hand files

. Stainless steel hand reamers

. Rotary NiTi used continuously or in an interrupted manner-great variety available

Given the dominance of rotary NiTi instrumentation, an analysis of the marketing strategy of the major brands including:

. Their being exclusively taught in the dental schools, supported by major financial incentives

. All alternatives to rotary are classified as “old fashion”

. Rotary being repeatedly stated that it represents “cutting edge” technology

. The “best” endodontists use them, the best being defined as the opinion leaders

. Hundreds of articles published about their clinically superior results

. Research touting their superiority over hand instrumentation as well as 30o oscillations

. The most ads

. The most lectures

. Largest booth spaces at the most meetings

.Most company reps

. Personal degradation of competitors

Many of these individual marketing tactics are mutually reinforcing. Examples:

. Instrumentation systems accepted by the schools are used in marketing with the corporations stating that the system was accepted because they were determined functionally to be the best.

. Equating acceptance with superiority are used in the ads, lectures and by the company reps.

. Emphasized in contrast to the “old technology” that has been abandoned by the dental schools for the “new technology”.

. The “best” endodontists burnish their reputations by using the “best” systems exemplified by their adoption in the schools.

. Studies address the reactions of students who are only acquainted with what they have been taught and can realistically only give non-comparative generally favorable responses on whatever training they received. Certainly, that is what will be reported.

Students at best can only compare rotary NiTi to the manual use of K-files. That is a stacked deck in favor of rotary NiTi. Students are also unlikely to have experienced instrumenting even mildly complicated pulpal anatomy because those clinical cases are likely done by the instructors. In short, they are for the most part too inexperienced to render well-informed opinions on what is available.

The end point of discussing the factors listed above is to determine how simple and predictable we can make the instrumentation systems without making them simplistic and thus, compromising the results. The rule in attempting to reach perfection, a goal never fully achieved, is not based on the concept of what can we add to make the system better, but when there is nothing more to take away.

Rotary NiTi is a safer system because torque sensing motors with varying speed controls were added.

Rotary NiTi is a safer system because a group of precautions were added while using them.

Rotary NiTi is a safer system because difficult cases may require a wider and more defined glide path added to the initial canal preparation prior to their use.

Once rotary was introduced, the problems encountered required additional tools to remove separated instruments.

A simple effective system should not need more and more precautions or additional armamentarium to take care of the problems that arise because a simple system does not produce added problems in the first place. In effect, it is the more complicated systems being used in a simplistic manner, namely, conservative centered shaping, that reduces the negative event of instrument separation, but at the expense of decreasingly effective debridement which is the reason we instrument canals in the first place.

I am sure there is at least more than one person who disagrees with my perspective, but the issues are certainly worth a collegial discussion.

Regards, Barry