Reciprocation Vs. Rotation: advantages and disadvantages.

The introduction of alternative movement to continuous rotation for NiTi rotary endodontic instruments gave to all endodontists another weapon to achieve an ideal root canal preparation. Reciprocating kinematic reduce the torsional stress of the file and open the possibility to complete the root canal shaping with less instruments, in many cases even a single file, and with less fear of torsional engagement and risk of fracture; fatigue accumulation using reciprocation is reduced as well increasing the lifetime of the instruments. On the other side reciprocating files, especially when used with a single file approach, tend to accumulate more debris in lateral anatomical spaces like isthmuses, untouched areas and lateral canals, creating more difficulties in cleaning these critical spaces. The differences in the use of continuous rotation instruments versus reciprocating ones will be explained in this lecture and possible tips and tricks to merge the advantages of both approaches.

Learning Objectives: Learning the differences in kinematics between continuous rotation and reciprocation, the indications for use of the different movements, the differences in the haptic feeling and in the hand movements of the operator, when use the “inbound pecking” and when use “outstroke brushing” and how to adapt the movement to different alloys, more austenitic or more martensitic, and to different sizes and design of the file.