Abstract: A denture base of pressure-formed, superplastic alloy plate, and a method of making a metal denture base, includes providing a superplastic alloy plate and a female die having a finishing surface, and pressure-forming the alloy plate on the finishing surface of the female die at a temperature where the alloy exhibits superplasticity.

Abstract: An orthodontic appliance for correcting teeth in a patient's mouth, has a bracket having a slot or groove and adapted to be secured to a tooth of the patient by means of an adhesive, a correcting wire placed in the slot or groove of the bracket, a magnet body having at least one magnet element, and a holder detachably attached to the bracket for holding the magnet body.

Abstract: An apparatus for diagnosing the environmental tissue of teeth, which has an electro-mechanical oscillation converter for converting the electric oscillation output from an electric oscillation output generation circuit into mechanical oscillation, a probe connected to the converter to be brought into contact with a patient's tooth for applying the mechanical oscillation from the converter to the tooth, and patient's responding means for actuation by the patient when he detects the sense threshold of the mechanical oscillation applied through the probe to the patient's tooth. Thus, a dentist can scientifically diagnose the health of the tissue of the patient's teeth as distinguished from the diseased part without visual examination nor palpation by the dentist.

Abstract: Phosphate derivatives represented by the formula ##STR1## wherein R represents a group containing at least one reactive double bond and A represents a group which may optionally contain reactive double bonds are disclosed. The phosphate derivatives of the present invention have at least two reactive double bonds, and polymers prepared from these phosphate derivatives in the presence or absence of other polymerizable monomers are useful as fillers for human hard tissues such as bones and teeth.

Abstract: A handy torch comprises a tank, a first valve mechanism, a second valve mechanism, a burner having a nozzle and an air-intake opening. A pipe connects the second valve mechanism with the burner. The first valve mechanism includes a first valve body having a cylindrical inner wall with a female thread and a valve seat, an actuating member having a male thread screwed with the female thread of the first valve body, a disc, a resilient O-ring disposed between the valve seat and the disc. The O-ring is designed such that the gas flowing from an entrance of the first valve mechanism can be controlled by the O-ring in cooperation with the disc and the valve seat. A suction material connects the male thread of the actuating member with the gas in the tank. The second valve mechanism includes a second valve body having a passage and a through-hole with a female thread, and a needle having a male thread screwed with the female thread of the second valve body for controlling the gas flowing through the passage.

Abstract: A cyclic pyrophosphate derivative having the formula ##STR1## wherein A represents a direct bond between the two phenyl rings or a divalent moiety selected from the group consisting of lower alkylene, aryl substituted lower alkylene, cycloalkylidene, sulfonyl and oxy;R.sup.1 represents alkyl, acryloyloxy lower alkyl or methacryloyloxy lower alkyl in which the lower alkyl can be substituted with halogen; andR.sup.2 represents independently hydrogen, halogen, lower alkyl or lower alkoxy;a method of preparing the same, a dental filling material comprising the same and a method of filling dental cavities are disclosed.

Abstract: Compositions capable of evaluating dental caries activity by making use of color reaction, which are composed of an aqueous solution containing coloring agents and water-soluble substances that are to produce an osmotic pressure higher than the physiological one on the cell membrane of cariogenic bacteria but free from any buffer action by themselves. Upon introducing dental plaque of a dental caries patient into this solution and thus measuring activity of the sordes by means of color reaction, it is possible to evaluate readily the status praesens of dental caries and its activity without any cultivation of cariogenic bacteria being required.

Abstract: Double fluid hardening resion compositions are hereby offered which contain a hardening resin base composed of bisphenol A epoxy resion and paraoxybenzoic glycydylester-ether epoxy resin and a hardening agent constituted by a complex of a polybasic carboxylic ester derived from an alcohol having a cyclic ether linkage in its molecule and boron trifluoride. These compositions are capable of very quick setting of resin and their hardened form possesses excellent physical properties, so that they are useful for urgent repairs of pipings, tanks, etc.

Abstract: A denture base is made of a photocuring resin compound by a process which includes polymerizing methacrylate and/or acrylate with the addition of a light sensitizer or a filler. Subsequent to a proper alignment of artificial teeth, the photo-curing or -hardening resin compound is hardened by exposure to light and artificial gingivae are formed by the same resin compound as above, followed by photocuring, thereby completing manufacture of the denture base.Advantageously, the method disclosed herein facilitates markedly the manufacture of denture bases in comparison with conventional methods such as thermal polymerization and casting. The resulting denture bases show excellent properties.

Abstract: A low melting point Ni-Cr alloy is fusible easily with a low-calorie heat source commonly and easily available. The alloy comprises, Ni, Cr, Cu, Mn and Al as the principal components thereof and an appropriate deoxidizer. There is further added at least one alloy element selected from the group consisting of Ga, Nb and Zr or other alloy elements if circumstances permit. The low melting point of the alloy disclosed herein simplifies casting facilities, makes plaster molds usable and facilitates the removal of products after casting.