Regarding the method used, Dr Kolzet complains that "the entire length of the dentinal tubules were infiltrated or contaminated." Yes, the idea was to get bacteria well into the tubules, or the study would not have been clinically relevant. However, the cementum on the root surfaces was kept intact to prevent bacteria from growing through the whole tubule.
Dr. Kolzet then claims that we did not use gloves and that the bacterial growth could be a result of contamination. The goal of this study was to investigate the ability of instrumentation techniques to eradicate dentin infection. This means that all measures were taken to avoid contamination, including the use of sterile gloves for each tooth and all controls—negative, as well as positive—to verify that contamination had not occurred. Also, the samples from the canals were—as described in the text—inoculated on Brucella blood agar plates and showed similar growth patterns to those of E. faecalis stock plates.
Dr Kolzet also brings up the importance of proper access for endodontic therapy and then claims that we did not have proper access preparations in the study. To emphasize his point, Dr Kolzet states that "one cannot paint a room through a keyhole." We have never tried this form of painting, but we agree that it must be difficult.
On a more serious note, every single endodontist agrees that access preparation is one of the most important parts of treatment. In our study, the crowns were removed prior to instrumentation. This gives you perfect straight-line access.
Dr Kolzet also claims that we have "condemned the use of laser technology." It is hard to understand how he can draw this conclusion from our article. We have only stated that none of the instrumentation, none of the techniques used in the study and neither Biolase nor Profile NiTi instruments could alone remove bacteria. When it comes to mechanical instrumentation, this is not a new finding, and the manufacturers of rotary instruments have never claimed that their products can do this.
Finally, we want to address another quote from Dr Kolzet’s letter: "The conclusion is not a valid one. Moreover, its inaccurate conclusion can serve to deter conscientious clinicians from delivering more comfortable and safe conventional and surgical endodontic therapy by discouraging its integrated use in patient care."
We all want to give our patients "more comfortable and safe conventional and surgical endodontic therapy." The way to achieve this goal is to seriously evaluate new methods, and not to accept often-exaggerated claims of manufacturers.
