A dental handpiece control apparatus including: a relay 17 that switches a polarity of a voltage applied to a motor 20, and thereby switches a rotation direction of the motor 20 to forward rotation and backward rotation, the motor 20 being incorporated in the dental handpiece to rotate a cutting tool (a file) mounted to the dental handpiece; and a control section 11 that controls the switching of the voltage polarity by the relay 17 based on a rotation angle θ.sub.F for forward rotation and a rotation angle θ.sub.R for backward rotation of the motor 20, the rotation angle θ.sub.F and the rotation angle θ.sub.R being associated with state information of the file.

A dental handpiece control apparatus including: a relay 17 that switches a polarity of a voltage applied to a motor 20, and thereby switches a rotation direction of the motor 20 to forward rotation and backward rotation, the motor 20 being incorporated in the dental handpiece to rotate a cutting tool (a file) mounted to the dental handpiece; and a control section 11 that controls the switching of the voltage polarity by the relay 17 based on a rotation angle θ.sub.F for forward rotation and a rotation angle θ.sub.R for backward rotation of the motor 20, the rotation angle θ.sub.F and the rotation angle θ.sub.R being associated with state information of the file.

A treatment device that shortens the time period until healing is determined even when a bone defect or a root apex lesion is generated in an apical area. The treatment device includes a file holder, a high-frequency signal generating circuit, and a control circuit. The file holder holds a file to be located in the site to be treated. The high-frequency signal generating circuit passes a high frequency current through the file. The control circuit controls a frequency of the high frequency current to be passed through the file from the high-frequency signal generating circuit. The control circuit controls the frequency of the high frequency current to be passed through the file within a range of 1.001 MHz to 11.700 MHz.

A treatment device that shortens the time period until healing is determined even when a bone defect or a root apex lesion is generated in an apical area. The treatment device includes a file holder, a high-frequency signal generating circuit, and a control circuit. The file holder holds a file to be located in the site to be treated. The high-frequency signal generating circuit passes a high frequency current through the file. The control circuit controls a frequency of the high frequency current to be passed through the file from the high-frequency signal generating circuit. The control circuit controls the frequency of the high frequency current to be passed through the file within a range of 1.001 MHz to 11.700 MHz.

A three-dimensional computer model of the patient's tooth, including the pulp chamber and root canals, is created by combining at least one grey value image of the tooth and/or surface information about at least part of the intra-orally visible part of the tooth with a statistical, parameterized shape model of each tooth type (upper or lower incisors, canines, pre-molars, molars) as the patient's tooth to be treated. This allows for planning and/or simulation of one or more root canal treatments on the computer model of the patient's tooth and that the dentist or dental specialist is given qualitative and/or quantitative information by the system in order to aid in adequately analyzing the risks related to performing the root canal treatment with the proposed or user-selected endodontic tools.

A three-dimensional computer model of the patient's tooth, including the pulp chamber and root canals, is created by combining at least one grey value image of the tooth and/or surface information about at least part of the intra-orally visible part of the tooth with a statistical, parameterized shape model of each tooth type (upper or lower incisors, canines, pre-molars, molars) as the patient's tooth to be treated. This allows for planning and/or simulation of one or more root canal treatments on the computer model of the patient's tooth and that the dentist or dental specialist is given qualitative and/or quantitative information by the system in order to aid in adequately analyzing the risks related to performing the root canal treatment with the proposed or user-selected endodontic tools.

An instrument for drilling dental root canals includes a tapered rod having over at least a part of its length—the active part—a polygonal cross-section forming at least two cutting edges, the active part terminating by a point and being defined by an envelope of cylindrical or conical shape, whose longitudinal axis coincides with the instrument's axis of rotation. The active part has a first portion extending from the point and a second portion extending following the first portion towards the rear of the active part. At least one cross-section of the first portion has a center of mass located on the axis of rotation and the cutting edges are located on the envelope. Any cross-section of the second portion has a center of mass offset with respect to the axis of rotation and at least one cutting edge defined by the cross-section is located set back.

A composition for tissue degradation and removal and disinfection is provided for dental and medical applications. It can function as a single intra-canal irrigant that eradicates microorganisms as it facilitates the debridement of a root canal system. It contains one or more hydoxides, a thioglycolate compound, sodium hypochlorite, sodium chloride, sodium chlorate, oxygen, and water, such as lime water and purified water, The thioglycolate compound is capable of degrading a cell by disrupting disulfide bonds in its proteins. The sodium hypochlorite enhances its function. The composition may also incorporate mineral oil, urea, cetearyl alcohol, D&C yellow No. 8, chromium hydroxide, theobroma cocoa seed butter, iron oxides, fragrances, lanolin, and/or ceteareth-20. It is effective against Enterococcus faecalis.

A composition for tissue degradation and removal and disinfection is provided for dental and medical applications. It can function as a single intra-canal irrigant that eradicates microorganisms as it facilitates the debridement of a root canal system. It contains one or more hydoxides, a thioglycolate compound, sodium hypochlorite, sodium chloride, sodium chlorate, oxygen, and water, such as lime water and purified water, The thioglycolate compound is capable of degrading a cell by disrupting disulfide bonds in its proteins. The sodium hypochlorite enhances its function. The composition may also incorporate mineral oil, urea, cetearyl alcohol, D&C yellow No. 8, chromium hydroxide, theobroma cocoa seed butter, iron oxides, fragrances, lanolin, and/or ceteareth-20. It is effective against Enterococcus faecalis.

An apparatus for endodontic treatment, comprising: a nozzle connected to a fluid source comprising: a tip small enough to be inserted into a pulp chamber of a tooth; an inner geometry which forms a flow parameters including non-axial flow direction of nozzle fluid flowing through the inner geometry such that discharge fluid discharged from the inner geometry increase rotation of root canal fluid within a root canal sufficiently to remove tissue from the root canal.