PERFEZIONAMENTO NEGLI STRUMENTI PER USO DENTISTICO, IN PARTICOLARE PER LA OTTURAZIONE DI CANALI DI RADICI DI DENTI ESTIRPATI

摘要

An instrument particularly adapted for thermomechanically condensing a thermoplastic material such as gutta percha in the root canal of a tooth through the rotative action of the instrument is disclosed. The instrument comprises an elongated member including a shank at one end and a working portion at its other end. The working portion is tapered along at least part of its length. The working portion includes at least two oppositely disposed, continuous helical flutes formed in at least a portion of the tapered length of the shank defining at least two oppositely disposed helical shoulders. The shoulders face away from the shank and make an angle with the longitudinal axis of the working portion of from about 90 DEG to 80 DEG and each of the continuous spiraled flutes make from about 1.0 to 3.5 spirals per millimeter along the longitudinal axis of the working portion of the instrument. Preferably, the tapered end of the working portion is provided with a generally cylindrical, smooth walled pilot having a generally blunt end projecting coaxially from the tapered end of the working portion.