Magnetostrictive materials have been utilized for the production of resonant ultrasonic-frequency vibrations for a number of years. This effect has been utilised in laminated nickel-based ultrasonic dental scaler cleaning systems. Laser vibrometry measurements were undertaken that showed that a typical dental ultrasonic scaler resonated at 29 kHz due to dynamic magnetostriction of the insert's laminated nickel 'stack.' This, in turn, excited insert probe vibrations that are used to remove dental calculus. 3D Femlab™ mechanical finite element models were created to explore the flexural vibration modes associated with the whole insert at the vibration frequency. These models indicated that it was possible to reproduce similar probe vibration mode-shapes to those seen via scanning laser vibrometry measurements. Also, the models indicate that vibrations, useful for dental scaling, can only be achieved if the coupled flexural and longitudinal resonant modes are stimulated at the same drive frequency.