This video shows how a vibration of a file reaches its natural frequency. V1 shows that an Eddy tip oscillates at its natural frequency while V2 shows an EndoActivator tip does not reach its natural frequency. Paying attention close to V1, less than a second the distal end of EDDY tip separates. This means that the EDDY tip achieved its natural frequency which causes damage due to excessive vibration while an EA tip does not separate. Vibration theory posits that every individual vibrating object will demonstrate both frequency and amplitude. Moreover, increasing the amplitude of vibration of an object is closely related to achieving either its natural frequency or one approximating it. In a real system, an object potentially has several frequencies with the result that achieving its natural frequency represents a challenge. By increasing the amplitude of an air sonic driven EDDY tip which produces forced vibration, it is possible to activate the solution during irrigation. The intense flow of the solution due to highest amplitude of vibration, natural frequency, of the tip produces near-wall high-velocity gradient which is proportional to wall-shear stresses. It is indicated that the natural frequency of the tip is critical. (PEETERS et al. 2022).
