Abstract: A dental handpiece is disclosed, which contains a handpiece body for giving dental treatment on a site in oral cavity of a patient, and an optical semiconductor device in the handpiece body for illuminating the site during the treatment. The optical semiconductor device is preferably LED, more preferably VLED.

Abstract: A dental treatment apparatus with a root canal length measurement function comprising a cordless handpiece equipped with at least a cutting tool drive motor, a root canal length measurement circuit and a power supply battery, and a charger equipped with at least a charge circuit for charging the power supply battery. With this structure, the handpiece can be operated as desired without interference with any tube since no tube is necessary to connect the handpiece to a main control unit, thereby capable of providing an easy-to-use treatment apparatus. By charging the power supply battery for the handpiece using the charger, the battery can be used repeatedly.

Abstract: The present invention discloses a handpiece having a root canal length measurement function, wherein a signal circuit, which is specifically provided for sending measurement signals from a root canal length measurement circuit to a measurement probe mounted on a head provided at the tip of the handpiece, is incorporated in the handpiece, and the signal circuit is electrically connected to the measurement probe via a contact piece in the vicinity of the measurement probe. Therefore, it is not necessary to connect the signal circuit for measurement by way of the outside of the handpiece. In addition, this structure improves the operability of the handpiece because there is no lead wire for connection. Furthermore, this structure eliminates the troublesome task of externally connecting lead wires to the head of the handpiece, which would otherwise be required at each treatment time.

Abstract: An image, sound and feeling simulation system for dentistry, comprising a dental handpiece having a drill for drilling a cavity in a tooth, the drill having a drilling end; a first three-dimensional sensor attached to the dental handpiece, the first three-dimensional sensor providing the system with position and orientation in space of at least the drill; and a data processing and display unit for simulating of at least the drilling end of the drill. The system further comprising means to control the flow of compressed air operating the drill and thus to control the rotation of the drill to imitate the sound and hand-feeling associated when drilling through tooth layers of different hardness.

Abstract: An inductive sensor is comprised of a sealed housing; at least one current path disposed in the housing; means for applying current to the current path; variable low reluctance magnetic path about the current path; and means for sensing the output from the current path as a function of variations in the magnetic flux path. Alternative current path configurations include a differential transformer, comprised of a permanent magnet or one or more primary coils in conjunction with two secondary coils, or a voltage divider, comprised of two primary coils. The variable magnetic flux path includes ferromagnetic fluid disposed in the housing to a level at which all coils are at least partially submersed. Tilt or other displacement of the sensor results in a change in the amount of fluid contacting the coils and a resultant change in current output from the current path means. The change in sensed voltage is indicative of displacement and sustained output voltage is proportional to the degree of tilt of the sensor.

Abstract: A device for alerting a dentist when the angular position of the drill and the angular position of the tooth being drilled do not correspond so that during drilling the angular position of the hole being drilled does not change. The device includes a drill transducer, a tooth transducer, a central control unit, and an alarm. The drill transducer is attachable to a dental drill and generates a drill angular position signal representing an angular position of the dental drill. The tooth transducer is removably attachable to a tooth and generates a tooth angular position signal representing an angular position of the tooth. The central control unit compares the drill angular position signal and the tooth angular position signal to each other to determine if the difference is within the value of a predetermined difference angular position.

Abstract: Repeat fixation for medical procedures is accomplished using a non-invasive locator, specifically a bite plate. The bite plate has at least three fiducial markers on it. The fiducial markers may be LEDs, radiopaque markers for angiography or computerized tomography (CT) imaging or magnetic resonance markers for magnetic resonance (MR) imaging. By detecting the position of the markers, the position of features within the patient (such as a brain tumor or other intracranial target to which radiation is to be applied) can be determined with great precision. Since the bite plate has been molded to uniquely fit to the patient's teeth, it may be removed after an initial imaging of the patient. The bite plate may then be re-attached one or more times to the teeth and the location of the features will be in a known position relative to the sensed markers.

Abstract: A method and apparatus for active cancellation of vibrational noise produced by a medical instrument in the head of a patient. Vibrations from the instrument, as well as vibrations in the bone structure in the head of the patient, are sensed and processed to generate cancelling noise waves which are then fed into the inner ear through headphones or through vibrators placed on the head of the patient. An equalizer shapes the magnitude and phase spectrum of the vibrational signal picked up from the drill and delivers the equalized signal to the patient. An automatic adaptive controller adjusts the equalizer using control signals consisting of vibrations from the bone structure and the drill.

Abstract: A system for effecting a desired modification in the shape of a pre-existing object to which access is restricted comprises, in accordance with the present invention, a computer, a first data generating device, a second data generating device, a display, an instruction input device and an output device. The first data generating device is operatively connected to the computer for providing the computer with electrically encoded data specifying a three-dimensional surface of the object, while the second data generating device is operatively connected to the computer for providing the computer with electrically encoded data specifying a curvilinear contour of the object. The display is responsive to signals from the computer for displaying a three-dimensional graphic representation of the object in accordance with data from the first data generating device and the second data generating device.

Abstract: The present invention relates to a dental drilling system having a programmable control unit. The control unit controls operating parameters of the drilling system, such as the direction of rotation, the speed of rotation and the torque of a tool bit of a dental drill, as well as the irrigation fluid flow rate generated by a pump and the intensity of light generated by a light source. The control unit can be programmed with a number of sets of data values. Each set of data values represents a desired value for each of the operating parameters to be controlled. Also, each set of data values corresponds to a different step in a dental operation. Thus, for each step of a dental operation, a surgeon can choose a desired set of operating parameter values from those sets that have been preprogrammed. The control unit then controls the operating parameters to achieve and maintain the values represented by the selected set of data values.

Abstract: The first purpose of the invention is to provide cordless light irradiation in which a stable amount of light is emitted when irradiating, and moreover, the device can be made compact. The second purpose is to offer a cordless light irradiation device that can control the battery temperature during use to a lower temperature than in the past.Halogen lamp 1 equipped with a reflective mirror and batteries 4 are housed in handpiece 2. The device is equipped with battery case 3 that is provided with ventilation holes 5, cooling fan 6 and optical filter 7, and lamp guide 8 is provided on the terminal of handpiece 2.

Abstract: A sensor for measuring angular displacement of a small body comprising a sealed housing containing a differential transformer having at least two primary coils, one primary and two secondary coils, or two primary and two secondary coils, said coils being partially submerged in a ferromagnetic fluid. Upon application of an AC current to at least the primary coils of the differential transformer, the voltage across the circuit defined by the two primary or the two secondary coils is indicative of the angle of tilt of the sensor and the body to which it is attached.

Abstract: A dental treatment is performed in accordance with examination of a patient and determination of a required sequence of treatments by a computer, based on the examination results.

Abstract: A suction control valve is disclosed which includes a primary suction device access and an ancillary suction device access. The valve includes an actuator which is movable between a first position in which the primary access is closed against suction pressure therethrough, to a second position in which the primary access is open to suction pressure therethrough, or alternatively, to a third position in which the primary access port remains closed to suction pressure therethrough and the actuator becomes locked against movement into the second position. When the actuator is in the first position, atmospheric air can pass through the valve and into the suction pressure source in such a manner that a "hissing" auditory signal is generated, indicative of the presence of suction pressure within the valve. When the actuator is in the second or third positions, the "hissing" is prevented.

Abstract: An automated periodontal probe uses a logic device to control the drive motor of a distendable probe rod. The movement of the probe rod is measurable and the force applied to the rod is quantifiable, therefore the device affords exacting repeatability of test procedures on periodontal tissues and permits an accurate survey of the gum pockets which survey may be displayed or recorded. Further the device can be calibrated to cause minimum discomfort to the patient.

Abstract: A root canal meter is disclosed, wherein measured data are compensated linearly or substantially linearly according to distance between tip of an electrode and apical position and thus compensated data are displayed. According to the invention interrelation between the position of the tip of the measuring electrode and the displayed value becomes clear and also, since the display scarcely varies in the early stage, there is no risk of any sudden change taking place in the vicinity of the apical position, hence the display is easily visible and the meter easy to use.

Abstract: A dental detection apparatus for the position of a root apex comprises two oscillators for generating the currents having two different frequencies passing between a single electrode contacting to a patient's body and a reamer, a differential amplifier for detecting the difference .DELTA.

Abstract: The digital apical foramen locating apparatus of the present invention utilizes the recognized fact that the conductance from the apical foramen to a patient's lip is not only equal to the conductance from the sulcus to the lip but is also constant from patient to patient. It further utilizes the recognition that there is a linear correspondence in the change of the conductance as the apical foramen is approached in root canal therapy. Utilizing this knowledge, the present invention employs a pair of fixed resistors to calibrate a single oscillator. This same oscillator is then used in the actual measurement and a comparison is made between the measured values and the stored reference values. In addition to a digital readout in 0.1 mm increments, there is an audible display whose cadence increases as the apex is approached and a graphical display which graphically illustrates to the dentist the location of the reamer in the canal and also the status of the probe's reliability.

Abstract: An improved method is proposed for releasing brackets from bonded joints whereby also ceramic brackets can be removed. Herein, the layer of bonding agent is subjected to pulse-shaped heat input by transfer of heat from an instrument to the bracket, with a safety device allowing only a suitable amount of heat for the respective type of bracket to be transferred.

Abstract: The modular dentistry apparatus comprises a plurality of modular operative blocks which each bear a respective instrument and have electric connection means and channels for supplying hydraulic and pneumatic power to said instrument which are suitable for being connected to similar connectors and power supply channels. The operative blocks are mutually associable in series by means of coupling means which comprise at least one pin which protrudes from a front face of each operative block and is adapted for coupling to a corresponding seat arranged on a rear face of an adjacent operative block and to be retained by locking means which are pneumatically actuated by means of a duct which is connectable to the pneumatic power supply channel of the instrument.

Abstract: A fiberoptic dental handpiece hose assembly has a smooth-walled, aseptic outer tubing that contains a plurality of internal components to provide drive air, an exhaust line, chip air and coolant water to the dental handpiece. The fiberoptic handpiece hose assembly is field-serviceable due to the rearend release connection of the outer tubing to the swivel assembly. This permits access to the internal components to allow repairs to be made in the dentist's office. The fiberoptic bundle is made from an acrylic material and the adapter is made generally from plastic to reduce the overall weight of the assembly and to improve the reliability and service life of the assembly.

Abstract: A recognition system is provided for tools, such as drill bits and milling bits, which are insertable into dental treatment instruments, each of the tools having an optimum speed at which the tool must be rotated for effective treatment. In the recognition system, each tool is provided with a code corresponding to the speed or speed graduation necessary to effectively use the tool. The system also includes a reader which reads the code on each tool, and generates identifying signals in accordance with the code, which are supplied to an evaluation logic. The logic converts the signal from the reader into control signals for the drive motor used to operate the tool, as well as indicator signals for visually displaying information relating to the tool currently in use.

Abstract: The apparatus prevents atomized fluid from being drawn back into the spray circuits of dental surgery instruments with separate air and water lines by virtue of incorporating a reservoir, installed on the air line at a point downstream of the relative control valve, the capacity of which is such as to ensure that air will continue to emerge from the instrument for a short duration after the control valve has closed.

Abstract: In dental surgery when a tooth is to be crowned, the tooth has to be prepared by cutting a taper. It has been found that for the successful mounting of a crown the taper must be much more exactly prepared than is possible using currently available equipment. The present invention allows the initial position of the axis of a cutter to be related by means of electronic "spirit levels" to a selected axis. Deviation from this axis by more than a predetermined amount is indicated by light sources which can be seen regardless of the position of a handpiece holding the cutter. By means of a code these light sources indicate how the dentist must move the cutter to return to the correct axis.

Abstract: A pneumatically operated machine such as a dental drill can be used with a pneumatically operated indicator capable of providing an audible signal such as a whistle or horn so provide an indication if the machine is stopped or is being operated in reverse. The indicator used is operated through the use of the pneumatic fluid normally used to operate the machine.

Abstract: A patient control mechanism is provided for an air conduit circuit that has a dental unit, a foot control and a compressed air source. The mechanism consists of a first valve disposed within the air conduit circuit between the dental unit and the foot control, a second valve directly connected to the first valve and a third valve disposed within the air conduit circuit between the dental unit and the second valve. A patient can manually control the third valve by sending an air signal to the second valve which operates the first valve deactivating the dental unit if pain is felt by the patient.

Abstract: An apparatus for conducting high-speed drilling bone tissue of varying density causing proportioned variations in the speed of the drill bur. A means is provided for automatically sensing the momentary bur rotational speed and producing either a visual or audible signal represented of the changing speed and its companion density.

Abstract: A method and system for obturating root canals are disclosed. The system includes filling points which are formed from a thermoplastic material and include an internal heating element axially aligned therein. By inserting the filling point into a prepared root canal and applying a moderate downward pressure thereon with an instrument which is capable of heating the heating element in situ, the thermoplastic material can be softened to effectively seal the main root canal and accessory canals without the need to insert instruments down into the canal system.

Abstract: A variable pneumatic output device for use with ophthmalic micro-surgical instruments including a reversible servo motor which operates in response to instructions from an electronic control circuit. The rotatable drive shaft of the servo motor is operatively connected to the adjustable level control of a precision pressure regulator which operates between a fully open level and a fully closed level. The pressure regulator is operatively connected between a pressurized air source and the pneumatically driven micro-surgical instrument and according to the instructions of the electronic control circuitry, the servo motor, through the connecting drive to the regulator, adjusts the level of pneumatic output to the surgical instrument.

Abstract: A numeric readout device is provided to display the distance of an instrument in a tooth from the peridontal membrane surrounding the tooth, including a pair of oscillator circuits with a numerical relationship determinator reading a distance measurement depended upon the impedance between the instrument and the gingival sulcus.

Abstract: A root canal implant is proximity indicative by reason of its electrical conductivity and comprises carbon fibers. Method of implantation is by means of endogenous heating within the prepared dental cavity, of the implant, and is the preferred method.

Abstract: A dental handpiece having therein a non-contact rotating speed detection device which includes an electromagnetic induction pulse generator including a permanent magnet provided close to the rotor in the head of a dental handpiece and a coil wound around the permanent magnet, and a rotor made of a magnetic material provided with recesses and/or projections around its circumference. The handpiece according to the invention facilitates to accurately detect rotor speed by detecting a pulse voltage proportionate to the rotation speed and therefore is useful for dental treatment and experiments.

Abstract: A novel and improved system is provided for detecting the apical constriction in the root canal of a tooth, in which the root canal, from which the dental pulp has been removed, is filled with electrolyte solution, a first electrode is put in contact with the mucous membrane in the oral cavity, a second electrode is put in the root canal, a fixed voltage or current is applied between the first and second electrodes, and a third electrode having an insulating coating except for the tip thereof is inserted into the root canal to detect sudden change in the potential along the root canal, and this change is visually and/or audibly indicated to indicate the apical constriction.

Abstract: An articulation detector for articulators of the kind wherein condylar elements mounted on a lower jaw member and glenoid fossae assemblies of an upper jaw member are made of a conductive material, comprises an electric power source, a luminous element and a pair of detecting electrode, all of which are connected in series. The electrodes are adapted to be connected to the lower jaw member and an incisal pin mounted on the upper jaw member of the articulator when the detector is in use. The adjustment of the articulator or prosthetic appliances may be detected by observing the light emitted from the luminous element.

Abstract: A circuit arrangement is provided for controlling the drive of dental treatment instruments by means of driving devices associated therewith and the operating data of which are adapted to be fed to a separate forward/backward counter when the particular treatment instrument is selected for use. A starter switch is connected to the forward/backward counter and is operable, when actuated, to vary the particular stored count of the counter step-wise for the purpose of varying the operating data and for transmission to a control element, for the control thereof, which is associated with the particular treatment instrument. Upon actuation of the starter switch in order to vary the stored count of the forward/backward counter, the counting speed of the counter is increased with increasing actuation time of the starter switch by reason of the fact that the counter receives a number of counter pulses which increase per unit time.

Abstract: One or more dental instruments are connected by flexible supply lines to a dental unit. A retractor is arranged to pull an extended instrument back to the unit upon being triggered. The dental instrument carries a magnet. A magnetic sensor is located near the retractor. When the instrument is passed near to sensor a signal activates the retractor which pulls in the instrument.

Abstract: Apparatus for the determination and the digital display of the position in the tooth canal of a root treating device, comprises a saliva suction device in circuit with the root treating device to sense the variation of the impedance between the gum and the root treating device. That impedance varies inversely as the depth of the root treating device; and so the variations in impedance are amplified and converted into DC voltage levels which are applied to a series of light displays in such a way that one light display will be most brightly illuminated while its neighbors will be less brightly illuminated, the comparative illuminations of the adjacent light displays giving a quick visual indication of the position of the root treating device in the tooth canal. An audible signal can also be provided.

Abstract: An improved apparatus for storing dental handpieces which includes a support device for each of the handpieces and a switching device for creating a signal when a handpiece is disposed in the supporting devices without contacting the handpiece. In one embodiment, the sensing device utilizes a light barrier which is broken by placing the handpiece in the supporting device and in another embodiment the sensing device utilizes a coil and resonant circuit whose output is changed by the presence of the handpiece.

Abstract: A system for concurrently supplying a liquid and drive gas to a gas-driven tool includes a drive gas source and conduit means connecting the drive gas source to the tool. Exhaust conduit means connect the tool to exhaust sensor means. A liquid source is connected to the tool by liquid conduit means. Means for causing liquid to flow from the liquid source to the tool is activated by means responsive to pressure of over a predetermined value at the exahust gas sensor.

Abstract: A root canal measuring apparatus can measure a length of a root canal without using an oral electrode. The apparatus is composed of an oscillating circuit having a relatively high output impedance, an output terminal connected to one output end of the oscillating circuit and also connected to a tooth electrode, another output terminal connected to the other output end of the oscillating circuit and also connected to a conductive portion forming an electrostatic capacity with a patient, and a display unit for displaying a variation in voltage between both the output terminals.

Abstract: This invention pertains to a water recycling system for economy in water consumption by dental evacuating equipment employing a water seal type pump and includes a storage tank for waste water received from the pump, a fresh water tank above the storage tank, and an air and water separator compactly arranged with said tanks, passage means between said tanks to permit makeup and flushing water to pass from the fresh water tank to the storage tank and flush the latter through syphon mechanism, except residual seal water remaining in the pump. Conduits extend from dental evacuating equipment to the pump and then to the air and water separator to vent air to atmosphere and pass waste water to the storage tank, and an additional waste water conduit extends in gravity-flow manner from the storage tank back to the pump for recycling and economy in water consumption.

Abstract: A dental hand engine for driving a reamer for widening root canals, which is characterized in the provision of a control device which electrically senses the time when a forward end of the reamer reaches a radical apex for automatically stopping the engine and consequently the reamer.

Abstract: An endodontic device for measuring and indicating the depth of penetration of a probe in a root canal of a tooth during a root canal operation includes a meter having a pair of juxtaposed, graduated scales for respectively indicating probe penetration depth in a first broad range of penetration within the root canal, and a second, relatively narrow range of penetration therein, adjacent the apex of the canal, and further includes a bidirectional indicator pointer to provide a precise, accurate visual indication of the probe penetration depth, particularly when such probe is immediately adjacent the apex of the canal. An a.c. measurement signal derived from a d.c. powered oscillator circuit is passed through the probe to a bridge circuit which measures the probe resistance, and thus the position of the probe relative to the canal apex, and also inverts the phase of the measurement signal when the probe reaches a prescribed penetration depth close to the canal apex.

Abstract: A water heater including an elongate tubular case, a block and a plug in spaced relationship in the case defining a chamber, an elongate heater tube with a helical portion within the chamber, and defining a central longitudinal opening, means connecting the ends of the tube with water supply and delivery lines, an elongate resistance heater unit extending longitudinally through said tube, an end extending from one end of the tube, a power supply line extending from a power source to the unit and means to control the supply of power from the line to the unit including a temperature sensing device positioned in the opening defined by the coiled tube and operable to stop and start the flow of power to the unit when the temperature of air in said opening is above and below a set temperature.

Abstract: A system for testing the dental pulp of a tooth by electrically stimulating the pulp with a pulsating signal having a continuously increasing amplitude. The system includes a probe having an electrode adapted to the tooth, and a contact device for sensing when the probe electrode makes contact with the tooth and for increasing the amplitude of the stimulus from an initial value. The intensity continues to increase as long as the probe electrode is in contact with the tooth. The electrical stimulus may be generated by a voltage controlled pulse generator driving the primary of a transformer, with the secondary of the transformer connected to the electrode probe. The transformer has a relatively low cutoff frequency so that the amplitude of the signal across the secondary is proportional to the pulse width of the incoming signal. Consequently, as the control voltage to the voltage control pulse generator increases, the amplitude of the pulses across the secondary also increases.