Abstract: An orthodontic bracket assembly is adapted for use with an arch wire in straightening a tooth having a crown long axis preferrably disposed at a particular angle with respect to an occlusal plane. The bracket assembly includes a base for fixing the assembly to the tooth and at least one tie wing having a fixed relationship with the base. The tie wing has a facial surface defined by a mesial edge, a distal edge, a gingival edge and an occlusal edge. At least one of the gingival edge and the occlusal edge are disposed at the particular angle with respect to at least one of the mesial edge and the distal edge of the tie wing, so that the facial surface of the tie wing has a generally rhomboidal configuration. This facilitates alignment of the assembly with respect to the occlusal plane and the crown long axis of the tooth.

Abstract: An indicator device which comprises a backing member, an indicator chemical, such as sebacic acid, which has the capability of wicking through a wick material, wicking means having one end of said wicking means in physical contact with said indicator chemical, said indicator chemical and wicking means being contained within a polypropylene envelope with the top and bottom interfaces of said envelope being sealed together to mechanically bond the wicking means and indicator chemical at the film envelope interfaces.

Abstract: A circuit protects a high voltage supply for x-ray tubes from the damaging effects of a tube flashover or the like. The circuit monitors line current, and high voltage and reacts to an increase in line current occurring with a corresponding drop in high voltage to turn off the high voltage.

Abstract: Test tube rack for holding a plurality of test tubes in an upright position and further adapted for holding the test tubes at slant angles of 5.degree. from horizontal and 20.degree. from horizontal for the preparation and growth of agar slant tube cultures or liquid tube cultures. The racks are further adapted for positive interlock stacking.

Abstract: A nonpermselective porous membrane sheet, which comprises a natural or synthetic fiber material substrate having coated thereon a mixture of a plastic binder material and a non-ion exchangeable filler material, said membrane being capable of transmitting negatively and positively charged ions between the electrodes in an electrodeposition painting operation and at the same time capable of preventing backflow of the electrolytes between the electrode chambers.

Abstract: Disclosed is a pressure adapter and containment vessel for converting a vacuum filter unit to use as a pressure filter. The containment vessel includes an off center well in the bottom of the vessel for supporting the filter unit, the off center well also providing a variable spacing between the wall of the containent vessel and the outlet spout of the filter unit. In addition, the containment vessel has a screw closure which cooperates with the cap of the filter unit to insure the filter unit is not pressurized until after the screw closure is properly attached to the containment vessel.

Abstract: Drawers for storage units such as dental cabinets are provided with a sealing system that eliminates the need for seal mounting partitions between vertically stacked drawers. Flexible seal members are attached to upper drawer handles, and these flexible sealing members contact the top of the next lower drawer handle when the drawers are closed, thus sealing the space between the drawers.

Abstract: An electric motor is supplied a voltage from a control circuit. The control circuit is powered by an AC to DC rectifier having a shunt capacity. An increase in motor load will result in lower speed and an increase in current. This causes an increase in AC ripple across the shunt capacitor. The control circuit is responsive to the AC ripple and increases voltage to the motor so that the speed set before the application of load is again attained.

Abstract: A surgical lamp includes a thermoplastic reflector which reflects visible light but passes infrared radiation. The reflector is fabricated from molded polyetherimide plastic resin. A dichroic coating is vacuum deposit directly upon the front surface of the reflector.

Abstract: A power supply provides high voltage for a grid controlled x-ray tube. In the supply an oscillator generates a high frequency signal which is amplified and transformed to kilovoltage. A voltage multiplier increases the kilovoltage to a potential suitable for the tube. The voltage multiplier includes a bank of series capacitors which tends to maintain a constant high voltage when the tube is not conducting.

Abstract: A system and materials for making oral impression trays in situ is disclosed, including a transporter member, tray member, and spacer member. Materials are disclosed for use as mold materials for polymerization in situ against or in close proximity to living tissue without high exothermal polymerization and its attendant discomfort and damage and with reduced polymerization shrinkage to produce a more accurate and stable custom tray.

Abstract: A fluid flow control valve uses a solenoid to control flow wherein the fluid path extends axially through the core of the solenoid. Flow is variable over the range of 0 to maximum flow and varies linearly with the voltage applied to the solenoid coil.

Abstract: Cabinet doors are supported by a hinge system that allows the doors to swing into an open space below the cabinet as they are opened. The hinge also reduces the room that must be provided in front of the cabinet to open the door. The door is mounted on hinge bars pivotally connected to a slide that rides on runners inside the cabinet. In the closed position, the bars rest on support pegs extending from the sides of the cabinet. As the door is moved forward, the hinge bars can pivot about the support pegs and the door can swing into the open space beneath the cabinet. Pivot pegs extend from each side of the cabinet in front of and below the support pegs, and the hinge bars contact the pivot pegs as the hinge bars pivot about the support pegs. The hinge bars then pivot about the pivot pegs, which control and limit the motion of the door as it moves into the fully open position.

Abstract: A dental syringe employs a single thumb or finger operated control member mounted on the syringe for regulating the flow of air or water or spray. The single control moves axially and vertically with respect to the syringe. Axial movement either forward or rearward from a rest position, initiates and controls the quantity of flow of air or water. Vertical movement of the control member initiates the flow of both air and water to produce a spray.

Abstract: An elastomeric dental impression catalyst composition for mouth temperature curing of liquid polythiopolymercaptan polymers comprised of propionic acid-treated, submicron zinc oxide and purified benzothiazyl disulfide (2,2.sup.1 -dithiobis-(benzothiazole)) is disclosed. The composition contains at least 20 parts by weight of the propionic acid-treated, submicron zinc oxide and less than 20 parts by weight of substantially pure benzothiazyl disulfide, with the amount of each of the zinc oxide and the benzothiazyl disulfide being based upon 100 parts by weight of the polymer. The final cured composition is also disclosed.

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: A disposable filtration unit wherein the body of the unit is a unitary, one-piece molded structure having an internal flange for dividing the unit into an upper and lower chambers, the flange also providing means for supporting the filter medium.