Abstract: A method of repairing or joining a metal oxide, such as Al.sub.2 O.sub.3, containing ceramic bodies, fired or unfired by preparing a sol from a precursor of the metal oxide, mixing with a gelling agent, Al(NO.sub.3).sub.3, to form a paste, optionally adding a reinforcement of SiC particulate and heating at an elevated temperature, and a repair kit.

Abstract: A composite made by milling Al.sub.2 O.sub.3 gel to a powder in the size range of from about 20 mesh to about 400 mesh, mixing said Al.sub.2 O.sub.3 gel powder with a reinforcement material consisting of SiC, SiO.sub.2, C, Al.sub.2 O.sub.3, ZrO.sub.2, Si.sub.2 N.sub.4, BN, B.sub.4 O, Y.sub.2 O.sub.3, TiC, TiB.sub.2, TiN and aluminosilicate, compressing and firing at an elevated temperature.

Abstract: A novel method for preparing sols from metal oxide precursors by using inorganic salts as the peptizing agent is disclosed herein. Sol-gels prepared from the sols are also disclosed. Ceramic coatings, monoliths, bodies and are formed. These structures have a particle size of down to 0.0001 micron and are endowed with excellent packing characteristics as well as smoothness.

Abstract: An electrosurgical instrument comprising a handle which holds a blade assembly comprising a plurality of electrodes and insulation members positioned between the electrodes.The blade assembly comprises a center electrode of specified thickness, insulation members secured to the center electrode and a plurality of side electrodes secured to the insulation members. The center electrode and insulation members are cut to form a cutting edge having a composite angle of less than 120.degree. thus allowing easier electrosurgical performance.The electrodes are connected inside the nonconductive handle to a circuit whose output consists of a high frequency electrical current which forms a circuit through tissue intervening between and in contact with the electrodes when the instrument is used.

Abstract: An electrosurgical instrument for cutting, spot coagulation and point coagulation comprising a nonconductive handle which holds a blade assembly comprising a plurality of electrodes and an insulation member separating the electrodes.The blade assembly comprises an active center electrode of specified thickness with a recessed tip and is mounted to an extruded insulation member so that it extends outwardly from the insulation member to form a cutting edge.Split side return electrodes are symmetrically mounted to the insulation member and separated from the center electrode by the insulation member. The electrode area ratio of the return electrode area to the active electrode area falls between 0.70 and 2.0 allowing consistent bipolar operation.The electrodes are connected inside the nonconductive handle to a circuit whose output consists of a high frequency electrical current which forms a circuit through tissue intervening between and in contact with the electrodes when the instrument is used.

Abstract: A glass-ceramic containing Li.sub.2 O, CaO, Al.sub.2 O.sub.3, SiO.sub.2, platinum and Nb.sub.2 O.sub.5 is disclosed. It is highly suitable for use in dental restorations because of its combination of castability, chemical durability and mechanical strength. The aesthetic qualities of natural teeth may be reproduced by proper control of processing parameters, e.g. addition of coloring additives and devitrification heat treatment schedule. Dental restorations may be made by casting a melt in a conventional dental laboratory investment mold, followed by devitrification. Fracture of cast margins is avoided because of the mechanical strength and toughness of the glass-ceramic. Partial restorations can be bonded with dental cement directly to the tooth of a recipient without the need for building the restoration upon an undercoat of metal alloy.