A dental treating apparatus according to the present invention includes: a hand piece; a head unit; a driving unit; a control unit; a load specifying unit; and a load comparing unit. The hand piece drivably holds a cutting tool on the head unit. The driving unit drives the cutting tool in a normal rotation direction or in a reverse rotation direction. The load comparing unit compares a load detected and a reference load. During a normal rotation period until driving for rotating the cutting tool in the normal rotation direction by the driving unit satisfies a predetermined first condition, the control unit maintains a rotation direction of the cutting tool in the normal rotation direction, and when a result of comparison by the load comparing unit attains a predetermined result during the normal rotation period, the control unit controls the rotation direction to the reverse rotation direction.

A dental treating apparatus according to the present invention includes: a hand piece; a head unit; a driving unit; a control unit; a load specifying unit; and a load comparing unit. The hand piece drivably holds a cutting tool on the head unit. The driving unit drives the cutting tool in a normal rotation direction or in a reverse rotation direction. The load comparing unit compares a load detected and a reference load. During a normal rotation period until driving for rotating the cutting tool in the normal rotation direction by the driving unit satisfies a predetermined first condition, the control unit maintains a rotation direction of the cutting tool in the normal rotation direction, and when a result of comparison by the load comparing unit attains a predetermined result during the normal rotation period, the control unit controls the rotation direction to the reverse rotation direction.

A reciprocating endodontic hand tool in which the torque applied to an instrument such as a debriding file can be set at or below an endurance limit of the file below which failure of the instrument will not occur. In preferred embodiments the tool can switch between settings in which the torque applied to the instrument is between the endurance limit of the file and an elastic limit of the file, by setting forward and reverse angles of rotation within specified limits. This reduces or eliminates opportunites for plastic distortion, fatigue and breakage of the file during the canal debriding/cleaning/shaping process in a root canal treatment or retreatment. In some embodiments the torque may be set to at or below a durability limit of the file below which failure of the instrument will not occur through repetitive strain over the course of a particular root canal treatment or retreatment.

A method for monitoring a failure of an endodontic instrument used during an endodontic treatment during which the instrument is driven by a handpiece and generates a set of acoustic emission signals, remarkable in that the method includes the steps of: sensing and analysing all of the acoustic emission signals generated by use of the instrument; and when a failure of the instrument occurs, thus generating a failure acoustic emission signal, detecting the failure acoustic emission signal amongst the set of acoustic emission signals in order to detect the occurrence of the failure.

A method for monitoring a failure of an endodontic instrument used during an endodontic treatment during which the instrument is driven by a handpiece and generates a set of acoustic emission signals, remarkable in that the method includes the steps of: sensing and analysing all of the acoustic emission signals generated by use of the instrument; and when a failure of the instrument occurs, thus generating a failure acoustic emission signal, detecting the failure acoustic emission signal amongst the set of acoustic emission signals in order to detect the occurrence of the failure.

A method for collecting usage data of an endodontic instrument. The method includes the following steps: acquiring data relating to the shape of a root canal to be treated; at regular intervals, acquiring data relating to the working depth of the instrument in the root canal; at regular intervals, acquiring data relating to the stress undergone by the instrument during work; and producing a database linking each data item acquired.

A method for collecting usage data of an endodontic instrument. The method includes the following steps: acquiring data relating to the shape of a root canal to be treated; at regular intervals, acquiring data relating to the working depth of the instrument in the root canal; at regular intervals, acquiring data relating to the stress undergone by the instrument during work; and producing a database linking each data item acquired.

A method for warning of an instrument break risk during an endodontic treatment. The method includes the following steps: acquiring the shape of a root canal to be treated; identifying a risk zone, on the basis of complexities in the shape of the canal, such as bends or bifurcations in the canal; in real-time, acquiring a working depth of the instrument; determining the position of the instrument within the canal, and issuing a warning when the instrument reaches the risk zone.

A method for warning of an instrument break risk during an endodontic treatment. The method includes the following steps: acquiring the shape of a root canal to be treated; identifying a risk zone, on the basis of complexities in the shape of the canal, such as bends or bifurcations in the canal; in real-time, acquiring a working depth of the instrument; determining the position of the instrument within the canal, and issuing a warning when the instrument reaches the risk zone.

A reciprocating endodontic hand tool in which the torque applied to an instrument such as a debriding file can be set at or below an endurance limit of the file below which failure of the instrument will not occur. In preferred embodiments the tool can switch between settings in which the torque applied to the instrument is between the endurance limit of the file and an elastic limit of the file, by setting forward and reverse angles of rotation within specified limits. This reduces or eliminates opportunities for plastic distortion, fatigue and breakage of the file during the canal debriding/cleaning/shaping process in a root canal treatment or retreatment. In some embodiments the torque may be set to at or below a durability limit of the file below which failure of the instrument will not occur through repetitive strain over the course of a particular root canal treatment or retreatment.