This ‘un’s for all you single file users; that’s a joke son, I say a joke

The images and videos of “The Root Canal Anatomy Project” blog were developed at the Laboratory of Endodontics of Ribeirao Preto Dental School – Univesity of Sao Paulo – and may be freely used for attributed noncommercial educational purposes by educators, scholars, student and clinicians. It means that all material used should include proper attribution and citation ( In such cases, this information should be linked to the image in a manner compatible with such instructional objectives. Enjoy! Click on the instructions as to how to download – all PowerPoint is .pptx


Dear Valeri and Craig: The only extra information I received from the manufacturer is that “One Shape is size 25 (diameter), with a 6%taper”. Nothing more than that. And I agree a 100% with both of you. The marketing is always the strongest point of dental companies. They need to sell… but we have an important task as educators (with no conflict of interest): to determine the pros and cons of such material. A single-file system of course is not the answer we are expecting. Actually, if we keep the same paradigm using instruments that cut in a round shape in a place where you have irregular and different shapes throughout the root, it will be always impossible to “touch” all of the dentin walls. It does not matter if we use manual, rotary, reciprocation, SAF, or whatever…none of them was able to completely clean and shape the root canal. A lot of people has already demonstrated that. And of course we have lots of thinks to discuss: irrigation, intracanal dressing, photodynamic therapy, and so on. So, I think we should move our way of thinking and move our thoughts to another level: do we really need to completely clean and shape the root canal? Clinical evidences show us that we do not need to do that…fortunately, we have some help from the host immune system. How much dentin walls we must left without preparation to promote health? How much bacteria can remain after the root canal preparation for an specific person? These are “THE” tough questions…On the other way, as an educator, I have the perception that it was easier to teach a fresh student how to deal with a single-file instrument in a reciprocating motion than with multiple files in a rotary motion. I do not know if you feel the same, but it was my experience. Thus, if someone shows me that with one file I can achieve the same result as with a sequence of them, I think we should give it a chance. I do not know what will happen. This things are so new and we had not enough time to test them all. In a recent (still non-published study) we compared all single-file systems with interesting results. It will be available soon for reading. But, in my practice I still use manual files for such a lot of things…a root canal with one instrument right now is completely impossible!

Hugs, Marco Versiani