A major goal of endodontics is the prevention or elimination of “apical periodontitis”. Apical periodontitis is the general term for endodontic-related periradicular/periapical inflammation, whether it is histologically a granuloma, cyst or abscess, in symptomatic or asymptomatic form. When root canal treatment is indicated, we rely on the triad of instrumentation, irrigation and obturation to achieve this goal.
Instrumentation has come a long way since we first started using NiTi alloy in root canal preparation. Initially research concentrated mostly on features of file design such as taper, cross-section, blade rake angle, pitch, tip design and so on. We then went on to improving the metallurgical properties of NiTi alloys for even more enhanced flexibility and fracture resistance. More recently we started also researching the kinematics of NiTi files in root canals in the search for optimised preparation.
Today we know a lot about the advantages and disadvantages of the features from all three categories, through the vastly accumulated evidence-based research. TF Adaptive, as a motor and file system, was brilliantly designed with a focus on providing the clinician with a huge set of beneficial features to hand while greatly reducing the potential limitations. During canal preparation the system shifts automatically between file rotation motion and reciprocation, each when most desired and appropriate.
This, in turn, results in an ability to prepare root canals safely (making file separation almost worry free) not only more quickly than before but also respecting the original canal trajectory, improving circumferential canal preparation and greatly minimising debris extrusion compared to other reciprocating systems.
Rotation vs. reciprocation
From the 90s,“traditional” NiTi root canal instrumentation has been performed through continuous instrument rotation. More recently, Yared (2008) introduced the concept of canal instrumentation with a single NiTi file using reciprocation movement. Since then, reciprocation has been the focus of much research, and designated motors and NiTi files have been brought to market. The benefits of reciprocation helped to make these file systems quite popular.
Over time, independent research has shed more light on these advantages, as well as the disadvantages, when comparing root canal preparation by reciprocation with traditional continuous rotation. We now know that continuous rotation remains superior to reciprocation in some scenarios, while the opposite is true in others. TF Adaptive is the only system to smartly empower the clinician with both features in one single programme mode. It does this via a sophisticated automatic torque algorithm that uses rotation when we want it and reciprocation when we need it. The system does this skillfully, eliminating the need for clinicians to switch between the programme settings on the endo motor during canal shaping.
In a reciprocating movement the file rotates in one direction, engaging and cutting the dentine, and then rotates back to a lesser degree, disengaging from the dentine. This extends the cyclic fatigue resistance on the file, reducing stress on the instrument to a degree where it is possible to prepare the entire root canal using a single NiTi file. This is usually not possible when using NiTi files in a continuous rotation motion and serves as a strong selling point for preparation by reciprocation vs. by rotation.