Abstract: A light-curing apparatus for curing polymerizable material in the mouth is provided. In one embodiment the apparatus comprises a wand which is substantially the same size as a quadrant or a full dental arch; in a second embodiment, the apparatus is in the shape of a dental tray and is adapted to fit over the outside of a dental tray; and in a third embodiment the light source comprises a portion (substantially the frame) of a double arch impression tray, and has a slide mechanism by which the mesh of a double arch impression tray can be removed from the light source so the light source can be reused. The invention also comprises a method for curing a dental material in the mouth using the apparatus of the invention.

Abstract: One component, visible light-cured dental restorative compositions having fluoride release properties for the purpose of reducing the chances of secondary caries are provided. The compositions include inorganic particulate fluoride leachable glass.

Abstract: An apparatus and method for curing light curable material using unfiltered light. A vented housing encloses a single lamp filament light source which emits visible light. The light source is positioned above and to the side of the light curable material which is supported on a rotating table during light curing. Light incident to the surface of the light curable material is at least about 50 milliwatts per square centimeter. The light curable material has a surface temperature of at least 150.degree. F. (65.6.degree. C.) after 2 minutes.

Abstract: A viewer system and method for evaluation of fluorescence of a test sample in comparison with a standard is provided. The system includes a viewer and test sample. The viewer has a fluorescence standard, a platform, a shield and an ultraviolet light source. The platform is positioned below the standard, the shield is adapted to enclose the viewing area and the ultraviolet light source is adapted to substantially simultaneously and equally illuminate the sample while the sample is supported in the viewing area by the platform. The sample is positioned for evaluating the fluorescence of the sample in comparison to the standard in the viewing area while the sample and the standard are substantially equally illuminated by the ultraviolet light source.

Abstract: The invention provides an improved dental/medical restorative/prosthetic composition employing a polymerizable unsaturated substituted butane moiety with acid or reactive acid derivative functionality having the general formula:(RO.sub.2 C).sub.x --C.sub.4 H.sub.6 --(CO.sub.2 R').sub.ywhere R is an acid radical or a reactive acid derivative and R' is a polymerizable unsaturated radical having from 2 to 13 C and x is 2 to 3 and y is 1 to 2.

Abstract: This invention provides hardenable compositions useful as construction media for a wide range of applications. Particular utility is found in the dental and medical arts where such compositions are highly suitable for the formation and construction of denture base, denture baseplates, denture liners, denture repair, custom trays, veneering for crowns and bridgework, artificial teeth, veneers and repair for natural teeth, and tooth restorative fillings. Such materials having improved impact strengths and elastic moduli when hardened are disclosed which include rubber-modified polymer.

Abstract: A heat cured pasty composition adapted to form a dental veneer which is resistant or immune to interdental cracks while in use on crowns and bridges. The composition includes polymerizable urethane-acrylic monomer, inorganic fillers, pyrogenic silica, heat activated polymerization initiators, and fractured organic filler particles. Heat polymerization of the composition above about 100.degree. C. forms a polymer which has a microhardness of at least HV 0.1/10 18.0 Kp/mm.sup.2, and an impact strength of at least 2.0 KJ/m.sup.2.

Abstract: Disclosed is a new urethane polyacrylate having at least one terminal isocyanato acrylic pendent radical. Preferably the molecular chain within the acrylate caps has been extended with a polyhydroxy compound just before final end capping with isocyanato acrylic. The isocyanato acrylic is preferably isocyanato ethyl methacrylate and the urethane is diisocyanate capped polyether and the polyether radical is oxyalkylene. The method for producing the urethane polyacrylate involves end capping a polyol with diisocyanate yielding a reaction product with two reactive equivalents of isocyanate and then capping less than all of the isocyanate with a hydroxyacrylate, after which the remaining isocyanate is reacted with polyol to provide chain extension. The chain extending polyol is then capped with a isocyanato acrylic.

Abstract: Range resolution in an FMCW radar system is achieved by providing a periodic linear frequency sweep. The present invention assures the linearity of this sweep by using a negative feedback circuit which includes means for obtaining 16 sequential instantaneous frequency versus time slope measurements during each sweep cycle, generating a set of 16 sequential error signals and a corresponding set of correction voltages, and applying these correction voltages to the sweep drive voltage used to drive the voltage controlled oscillator that generates the frequency swept output signal.

Abstract: An apparatus for scaling of teeth and lavage of the gingival sulcus is provided. The apparatus comprises a base unit which contains reservoirs for the medicaments used in the lavage procedure, and a handpiece connected to the base unit by a conduit, which contains an insert for scaling of teeth. Switches on the base unit and a footswitch make it possible for the practitioner to use the apparatus for scaling only, lavage only, or for simultaneous lavage and scaling.

Abstract: A method and apparatus determines a quantity of liquid in a tank when at least one liquid sensor is inoperative. In a first embodiment, a plurality of tables are stored in memory which are grouped by identities of the possible inoperative sensor or sensors. One group of tables is selected based on the identified inoperative sensor or sensors. Then, that one group of tables is accessed, and the quantity of liquid in the tank is calculated based on the readings of the operative sensors. In a second embodiment, a first plurality of tables stores quantity readings for each sensor as if all sensors are operable. A second plurality of tables includes one table for each possible configuration of inoperative sensor or sensors. When the inoperative sensor or sensors are identified, one particular table in the second plurality is accessed and a quantity amount is then added to the liquid quantities determined from the first plurality of tables to provide a total liquid quantity in the tank.

Abstract: A test system viewer for fluorescence evaluation has been designed to facilitate the simultaneous evaluation of multiple test samples, to provide consistency in the process for the evaluation of the fluorescence and to protect the operator from the harmful effects of the ultraviolet radiation associated with the viewer.The viewer contains a base and a viewing shield, with the base having the fluorescent light source and an internal fluorescent standard. The viewing shield contains an internal ledge and a viewing area with a fixed viewing angle to the internal fluorescent standard. The internal ledge and the viewing angle cooperate to block ultraviolet rays from the fluorescent light source and to prevent the operator from directly viewing the light source during operation of the viewer. The use of a fixed light source, internal standard, viewing area and viewing angle insures observation consistency during the evaluation procedure.

Abstract: A transducer system and method of use thereof by sequentially operating a comparator to produce a series of pulses in which the time distribution of the pulses is representative of the transducer value, and is used to normalize the sensed value in the event that the total transducer value varies due to environmental influences. The transducer is adapted to monitor the substantially linear movement of the level (fuel-air interface) of fuel in a tank and the angular positon of an input shaft.

Abstract: System and method of error reduction in which a comparator is sequentially operated to produce series of pulses in which the time distribution of the pulses is related to the displacement being monitored by the transducer. In particular, the comparator is sequentially operated to provide two sets of pulses using a positive ramp voltage, and then using a negative ramp voltage having a magnitude equal to the positive ramp voltage. Averaged time periods between the pulses are used to eliminate offset errors in the determination of the value that the transducer is monitoring. The transducer is adapted to monitor the substantially linear movement of the level (fuel-air interface) of fuel in a tank and the angular position of an input shaft.

Abstract: System and method of error reduction in which a comparator is sequentially operated to produce series of pulses in which the time distribution of the pulses is related to the displacement being monitored by the transducer. In particular, the comparator is sequentially operated to provide two sets of pulses using a positive ramp voltage, and then using a negative ramp voltage having a magnitude equal to the positive ramp voltage. Averaged time periods between the pulses are used to eliminate offset errors in the determination of the value that the transducer is monitoring. The transducer is adapted to monitor the substantially linear movement of the level (fuel-air interface) of fuel in a tank and the angular position of an input shaft.

Abstract: A system and method for providing a constant rate of sparking in the spark gap of an internal combustion engine by supplying constant power to the capacitor which discharges through the spark gap. The capacitor receives current from the secondary coil of a transformer. The system uses a multivibrator to control current flow through the primary circuit of a transformer. The multivibrator is controlled by a comparator which compares an integrated transformer feedback signal to a temperature compensated reference voltage. In any two equal time periods, substantially the same amount of current flows to the capacitor from the secondary of the transformers. Substantially the same number of sparks are discharged through a spark gap during equal time periods.

Abstract: An optical fiber mounting device and method of installation and monitoring of a structure using the device. The device includes an optical fiber connected to a support sheet. The support sheet is readily adapted to be connected to a structure. The method of installation of the device includes affixing the support sheet to a structure. The fabricated structure is monitored by propagating light through the installed optical fiber and continuously monitoring the light to detect changes in temperature, pressure, stress and/or strain in the structure.

Abstract: A simple form of woodwind instrument of the clarinet-type and flute-type is shown. Each instrument utilizes the same body made of PCV pipe and different sound generators of clarinet-type mouth pieces or flute-type head joints designed to fit the body. The instrument is intended for beginners in a general music classroom setting grades 1 through 6, possibly complementing the "Orff instrumentarium" of percussion instruments. The simplified instrument may be used along to provide "hands-on" introduction to the legitimate woodwind instruments (clarinets and flutes) in a step-by-step preparation for playing these instruments.

Abstract: A combination mixing and discharge capsule for storing separate ingredients which are to be mixed together prior to use and including a container body for one ingredient closed at one end by a slidable piston and the opposite end being displaceably received in a cup-shaped cap which forms a second compartment with a perforated wall of the container body opposite the end containing the piston for receiving a frangible pillow containing a liquid second ingredient to be mixed with the ingredient in the body. The cap has a discharge nozzle extending axially therefrom and when the cap is displaced farther onto the body the innermost wall of the pillow is burst to cause the discharge of the liquid ingredient through the perforated wall end into the container body for mixing with the ingredient therein.