Abstract: An automatic drive circuit for an ultrasonic probe, such as a dental scaler insert, is operative with a probe which includes a magnetostrictive unit and a vibratory element to be set into vibration by the magnetostrictive unit upon energization of the magnetostrictive unit with an alternating magnetic field. An energizing coil is enclosed within a handle having a compartment for receiving the probe. The coil is located within the handle adjacent to the probe-receiving compartment for applying the alternating magnetic field to the magnetostrictive unit upon insertion of the probe into the handle and upon energizing the coil by the drive circuit. An oscillator of the drive circuit is coupled to the coil for applying an oscillatory current to the coil. The drive circuit includes a frequency sensor for sensing a frequency of the oscillatory current, the sensor outputting a signal designating a magnitude of the frequency.

Abstract: A strobe light curing apparatus which includes trigger electronics for producing a series of pulses at a predetermined frequency. A flash lamp is coupled to the trigger electronics for producing flashing light according to the series of pulses. A reflector is further disposed from the lamp at a first predetermined distance for reflecting and focusing the flashing light at a second predetermined distance.

Abstract: A dental disc and sleeve assembly for removably coupling die portions of teeth from a dental model onto a cast base. The disc is inserted into a semi-circular cut formed in the underside of the die portions so that the disc is secured in the die and partially protrudes therefrom. A sleeve secured in the cast base has a head portion having a chamber matingly receiving the protruding portion of the disc and a tail portion. Two knobs provided on the opposite sides of the disc are snapped into two grooves formed at two opposite sides of the chamber. The grooves can release the knobs and the disc can be removed from the sleeve when slight pressure is applied to the tail portion of the sleeve to remove the die portion from the cast base.

Abstract: A dental post for securely retaining a dental restoration in a prepared tooth stub. The dental post is formed of an elongated cylindrical rod having an active threaded portion and a passive portion. The dental post is threadedly engaged with a sleeve secured in the tooth stub, which sleeve has at least an active threaded portion.