A Response To The Critic On Precautions Regarding The Use Of Laser-Activated Irrigation Systems

Being thoroughly impressed as everyone else regarding the extremely tortuous canal pathway that evidenced filling material to the apex, what caught my attention was the fact that the rotary instruments and the tip of the laser were never closer to the apex than half-way down the root. The implication of this observation is that the lasers employed enough energy at a distance to remove the tissue from the canals all the way to the apex, a distance of several mms.

The literature discusses precautions that should be take because of this ability to produce action at a distance. They are not to be used where open apices are present or in close proximity to sinuses. Noting that blood at times extruded into the canals from the tissue beyond the apices, it is reasonable to assume that action at a distance includes enough energy to produce such effects, effects that common sense tell us we don’t want implemented if for example the inferior alveolar nerve is in close proximity to the tips of the roots. I brought these points up as a precautionary note, that we should be aware of unintended consequences, that the energy required to have action at a distance is a potential source of harm recognized by the manufacturers by stating where their use should be limited.

Noting the necessity for these limits, the action of an irrigation system limited to its physical presence in the canal would logically do away with this concern. These limited conditions are employed when using the 30o oscillating reamers at a frequency of approximately 60 cycles per second. The action the irrigants present in the canals is highly effective as evidenced by the French study with the advantage of being limited to the confines of the root. There is no action at a distance that can lead to unintended consequences.

My goal in stating these concerns is for dentists to pause in our awe of unbelievable mechanics and better appreciate the implications of what such energy dispersal can do beyond the confines of the root. What I bring up may or may not be clinically relevant, but for sure it should not be dismissed as a denigration of an extremely impressive result. Nor is there any place for the critic’s pension for personal insult.

As an academic, he should welcome challenges that question potential downsides and provide answers that effectively neutralize these concerns. On the other hand, if the stated concerns are real, it is important for dentists to not only see the spectacular results that can be attained, but also be equally aware of the precautions and limitations when considering their use.

Personally, I always like the teacher who says there are no stupid questions. That might be stretching the truth, but when it comes to education, the last thing we want to impose on anyone is intimidation. So being charitable and expansive would seem to set the conditions for enhancing a dialogue. After all, the next question from a person who first asked a “stupid” question might be brilliant and denigrating an individual for that first question would likely discourage that individual from asking the next question. The critic should be aware that as the academic he designates himself as, his role is to encourage critical thinking and not set himself up as judge and jury of what is allowed to be discussed. As uncomfortable as that may be for him when confronted with alternative outlooks, personally degrading remarks are not the answer. In fact, an absolute answer may not be forthcoming, but the process of evaluating and interpreting data is the method by which our intellects are stimulated and our critical skills improved.

Regards, Barry