Abstract: A dental root canal diagnostic and treating equipment with which specific position/s, which serve/s as the reference positions, can be set arbitrarily and such positions can be displayed. With the equipment, therefore, operation can be proceeded with knowledge of not only the position of the tip of the root canal instrument, which also serves as the measuring electrode, but also the remaining distance to the reference position.

Abstract: A dental handpiece holder adapted such that the length of the handpiece holder for holding and accommodating a dental handpiece is shortened in the axial direction, whereby the main unit of the handpiece can be attached to and detached from the joint section of the handpiece for the purpose of replacement with one hand of an operator. Also a dental treatment assembly by use of the holder.The handpiece holder comprising a gutter-shaped receiving seat, first and second grip sections extending from both side fringes of the receiving seat, contact sections formed at the leading ends of the first and second grip sections respectively and an engagement groove or projection extending across the contact sections or the peripheral areas thereof in the internal circumferential direction of the grip sections.

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: The apparatus of the present invention comprising a rotary means having an X-ray source disposed opposite to an X-ray image detection section for detecting the image of the X-ray which penetrated an object to be photographed, with the object positioned therebetween, and rotating the X-ray source and the X-ray image detection section as an integrated unit around the object, an image storage means which sequentially stores image information obtained by the X-ray image detection section as frame images, and an image processing means which sequentially derives image information from the image storage means at predetermined time intervals, adds the information of each image while shifting the information of each image by a predetermined distance in the image movement direction along a series of image information to digitally form the panoramic image of a given tomographic image layer depending on the interval for deriving the information of each image and the shift amount.

Abstract: A medical X-ray image detecting device wherein the fluorescent surface of a narrow belt-shaped X-ray fluorescen plate which emits light at the time of irradiation of X-ray through a slit is divided to rectangular units, optical fiber bundles are distributed alternately right and left and arranged vertically, the one end surface of each optical fiber bundle is attached to one of the divided fluorescent surface unit, the other end surface of each optical fiber bundle is attached to the image pickup surface of a solid-state image pickup device to make image formation possible, and the solid-state image pickup device is disposed behind an X-ray shielding member by which the slit is formed.

Abstract: An apical position detection apparatus for detecting an apical position depending on the change in the impedance between a measuring electrode inserted in a root canal and an oral electrode connected to a soft oral tissue, the apparatus being characterized in that it comprises a signal output means which applies measurement signals with different frequencies between the measuring electrode and the oral electrode and a relative ratio detection means for calculating the ratio of root canal impedance values obtained depending on the measurement signals, whereby the detection apparatus detects the apical position by sensing that an equivalent impedance decreases and that the ratio of the root canal impedance values changes as the leading edge of the measuring electrode approaches the apical position. A method for detecting the apical position by using this apparatus is also disclosed.

Abstract: A medical panoramic radiographing device comprises in combination a mode selector which is used to select the panoramic radiographing mode, jaw joint radiographing mode and/or otolaryngological region radiographing mode, an X-ray irradiation timing determination means which is used to determine the X-ray irradiation timing appropriate to the rotation positon of a rotary arm in the sselected radiographing mode, and an X-ray film movement pattern determinator which is used to determine movement patterns regarding the movement timing, speed, etc. of an X-ray film depending on the selected radiographing mode. With this device, the X-ray irradiation timing values or the X-ray film movement timing values suited for various radiographing modes are set automatically to ensure systematic selection of various radiographing modes.

Abstract: A laser irradiation device comprising an optical fiber, a contact probe which irradiates laser light from the irradiation end section thereof, and a holding member which coaxially secures the contact probe and the optical fiber. The device is further characterized in that the irradiation angle of the laser light irradiated from the irradiation end section of the contact probe can be changed while the diameter of the contact probe is standardized, whereby the irradiation angle and diffusion conditions of the laser light can be set and changed as desired to improve the transpiration and coagulation capabilities using a low output laser generation unit, thus reducing the coast of the entire laser irradiation system.

Abstract: A dental panoramic/cephalo X-ray photographing device being characterized in that an X-ray generator can be horizontally rotated by an electric drive means so that the X-ray irradiation axis of the X-ray generator is directed to a panoramic photographing cassette or a cephalo photographing cassette.With this device, selection between the panoramic and cephalo photographing modes can be done far quicker and more accurately than devices of the prior art.

Abstract: A dental radiographic apparatus for photographing the entire jaws in which the apparatus includes a rotary arm having an X-ray source at one end and an X-ray film cassette at the other end thereof and operating in the manner that a path of movement of X-ray beam with respect to the dental arch describes a symmetrically extending approximately triangular envelope projecting toward the front tooth region of the dental arch by sequentially shifting the center of rotation of the X-ray beam irradiated from the X-ray source upon the X-ray film cassette, the apparatus being characterized in that it comprises a means for changing the straight-line distance on the medial line of the human body between the apex and receding points of limit of the envelope.

Abstract: An investment compound for use in a precision casting mold comprises MgO powder and Al.sub.2 O.sub.3 powder as main constituents in such a manner that the MgO powder and/or the Al.sub.2 O.sub.3 powder are or is in the range of 100 .mu.m or less in grain size and of 10% or more in weight precent, whereby even when a high-temperature active casting material such as titanium is used, the material provides a casting having a very beautiful surface with no bubbles formed therein and can positively compensate for shrinkage due to the solidification of cast material in a lost-wax process and can advantageously provide the casting at lower prices.

Abstract: An image picking-up and processing apparatus particularly suitable for use in dental treatment comprises a transmission and conversion section including an image sensor for detecting input light from an object, an objective lens, and a light guide for transmitting illumination light; a control section including a control unit for producing an image signal on the basis of an output signal from the image sensor, and a light source for emitting the illumination light; and an interchangeable image processing section detachably connected to the transmission and conversion section for processing the image signal to reproduce image information in a desired form. An interchangeable image picking-up section, for example, an endoscope including an objective lens, an image fiber for transmitting the input light, and a light guide for transmitting the illumination light is detachably connected to the transmission and conversion section.

Abstract: A patient positioning device in a medical panorama X-ray photographing apparatus in which after data of the relative position of the subject to the X-ray photographing apparatus supplied from a sensor is compared with data of the relative position of a tomographic zone to the X-ray photographing apparatus thus to produce comparison data which is in turn transmitted to a drive circuit, a tomograph forming assembly and/or the subject is moved from coinciding with each other. The device further includes a comparing arithmetic circuit in which the detected position data of the subject and position data of the tomographic zone are arithmetically compared in order to improve operatability and positioning accuracy. The device furthermore includes a sensor which is adjustable for angular and vertical setting with the use of sensing position changing means in order to improve adaptability to individualities of the subject.

Abstract: A laser-type handpiece including a reflector pivotably connected inside a head section and a control sleeve which is connected to the reflector and fitted over the external circumference of the handpiece body so that the sleeve can move back-and-forth along the axis of the handpiece body, whereby the reflector can be adjusted to any desired angle by the back-and-forth movement of the sleeve. When this handpiece is used for dental treatment, the head section of the handpiece can be smoothly inserted into and taken out from a narrow oral region and the angle of laser beam can be changed easily.

Abstract: A treatment chair assembly comprising a treatment chair and a chair base, the chair assembly being pivotally or swingably connected to a chair base, in which a chair elevating mechanism is housed, so that the chair can be turned upward from and downward to the chair base. With this treatment chair assembly, it is not necessary to separate the treatment chair from the chair base and move the treatment chair to a different place when the chair elevating mechanism and the instrument drive/control unit are maintained, checked or repaired. The treatment chair can be turned upward by pivoting or swinging without separating and moving the treatment chair. As a result, labor can be saved and no space is required to temporarily store the treatment chair. The space for a dental treatment room can be used effectively. Furthermore, since the chair is not separated or moved, less concern for staining or breaking the chair due to bumping against objects is necessary.

Abstract: A medical laser handpiece comprising a grip body, a semiconductor laser generator disposed in the grip body and an irradiation nozzle which is detachably cross-connected to the head of the grip body at an angle and includes a laser light transmitting means from the semiconductor laser generator. With this laser handpiece, an operator can accurately and easily treat even relatively small and complicated shaped teeth and periodontal sections in the mouth. In addition to a structure capable of irradiating laser lioght and a structure capable of cooling the semiconductor generator, this invention also includes a structure capable of jetting air, water and a mist of air and water, and a structure capable of reducing irradiation loss of laser light.

Abstract: A pre-ignition type X-ray apparatus including a mode changeover switch which changes a pre-heat mode to an X-ray irradiation mode and vice versa, a tube current control circuit for feedback control of the X-ray tube's filament heating current to a target value, and pre-heat control circuit for controlling the filament heating current in the pre-heat mode to a target value lower than the target value in the X-ray irradiation mode. The pre-heat control circuit includes a differential amplifier which amplifies the difference between the detected voltage corresponding to a source voltage and the reference voltage determining the lower target value, so that the control signal is outputted from the differential amplifier.

Abstract: A connecting means for an illuminant handpiece being characterized in that the connecting device is adapted such that at least one of the electrical connections of the electric power receiving terminals of the illumination lamp and the electric power supply terminals is performed by fitting at a position close to the axis of the grip section almost symmetrically about the axis, and the other electrical connection is performed by fitting almost symmetrically about the axis or by abutting coaxially about the axis so as to permit a mutual rotation of the terminals. With this structure, the diameter of the connection area can be made small and the grip section can have an easy-to-hold size. In addition, the distance to the irradiation section can be reduced and efficient irradiation with less optical loss is obtained. Moreover, the space or lamp replacement can be reduced.

Abstract: Metal material is melted by moving the magnetic flux of electromagnets virtually perpendicular to an arc column to apply Lorentz force to the arc column and the metal material so that the arc column can move over the metal material surface. The movement direction and speed of the arc column are determined by detecting the arc voltage of the arc column. Feed back control is performed by comparing the obtained detection data with preset data so that optimum control is performed, and the molten metal is poured into a casting mold.

Abstract: A dental lighting device arranged such that the light from a light source is reflected by a reflection plate and is cast into the inside of the mouth, wherein a mirror member used to look at the inside the mouth is provided in combination with a lighting device component so that the mirror member can take a mirror use posture where the surface of the mirror member is almost perpendicular to the light beam from the reflection plate at least when the mirror member is used. The mirror member of the lighting device can also take a mirror non-use posture where the mirror surface does not intercept the light beam.