Abstract: A method, system and computer program product for controlling data access through a question and answer mechanism, including assigning a unique user identification for a user; associating information of the user with the user identification; receiving a request for the information based on the user identification; generating a question, based on a relationship between the user and a requestor of the information, that the requestor of the information must answer in order to access the information; and providing access to one of a portion of the information and all of the information, based on the relationship between the user and the requestor of the information, if the requestor correctly answers the question.

Abstract: A bone cement in pliable and moldable form which when applied to bone and cured has superior characteristics containing an admixture of methylmethacrylate copolymers, methylmethacrylate, and between 15 and 75% by weight of an inorganic composition of between about 90 and 99% of a bio-active glass ceramic powder having a particle size of 10-200 micrometer and between 1 and 10% of vitreous mineral fibers having a length of less than 20 mm. The composition also contains a curing catalyst and, preferably, an accelerator.

Abstract: Polymerizable hydrox-group-containing diesters of acrylic acids for dental material are prepared by reacting 3-(3,4-epoxycyclohexyl)-8,9-epoxy-2,4-dioxaspiro(5,5) undecane or a bis-epoxide of formula (A) ##STR1## or a bis-epoxide of formula (B) ##STR2## with a hydroxyalkylacrylate or hydroxyalkylmethacrylate containing 2 to 10 carbon atoms in the alkyl portion, n being 0 or 1 in formula (A) with the proviso that whenn in 0, X is --O-- and R.sup.1 is --H; and whenn is 1, X is selected from the group of alkylene with 1 to 10 carbon atoms, C.sub.1-3 -alkyl substituted alkylene with 1 to 10 carbon atoms, --O--(CH.sub.2).sub.m --O-- where m is 1 to 10, --CH.sub.2 --OCO--(CH.sub.2).sub.p --COO--CH.sub.2 where p is 1 to 6, and --CH.sub.2 --OCO--, and R.sup.1 is --H or --CH.sub.3,and in formula (B) ##STR3## OR TRICYCLO-[5,2,1,0.sup.2,6 ]-DECYLENE.

Abstract: A bone cement composition includes, as the principal component, powdered copolymers of methyl methacrylate and methyl acrylate, or monomeric methyl methacrylate, and, in addition, gentamicin hydrochloride and/or gentamicin hydrobromide, or a mixture of gentamicin sulfate with sodium chloride, potassium chloride, sodium bromide and/or potassium bromide. The bone cement composition is used, for example, for cementing implants in place, for the anchoring of endoprostheses of the joints, in the treatment of skull defects, and for carrying out spinal fusions. The composition provides for antibiotic release in higher concentrations to prevent infections.

Abstract: The present invention provides prosthetic dental appliances which contain at least one outer surface portion which includes an outer surface of the appliance which is adapted to be polished and which is highly abrasion resistant. Said shaped body portion is a hardened matrix material containing amorphous silicic acid filler particles of a maximum particle size of about 0.07 micrometer. Preferably, at least 30% of the body portion comprises the filler particles. The polymeric matrix is preferably a hardened organic resin. The invention also includes the hardenable material comprising a hardenable matrix having filler paticles dispersed therein which is used to produce the hardened prosthetic dental appliances.

Abstract: Polymerizable hydroxy-group-containing diesters of acrylic acids for dental material are prepared by reacting 3-(3,4-epoxycyclohexyl)-8,9-epoxy-2,4-dioxaspiro(5,5) undecane or a bis-epoxide of formula (A) ##STR1## or a bis-epoxide of formula (B) ##STR2## with a hydroxyalkylacrylate or hydroxyalkylmethacrylate containing 2 to 10 carbon atoms in the alkyl portion, n being 0 or 1 in formula (A) with the proviso that whenn is 0,X is --0-- andR.sup.1 is --H; and whenn is 1,X is selected from the group of alkylene with 1 to 10 carbon atoms, C.sub.1-3 -alkyl substituted alkylene with 1 to 10 carbon atoms, --O--(CH.sub.2).sub.m --O-- where m is 1 to 10, --CH.sub.2 --OCO--(CH.sub.2).sub.p --COO--CH.sub.2 where p is 1 to 6, and --CH.sub.2 --OCO--, andR.sup.1 is --H or --CH.sub.3,and in formula (B) ##STR3## or tricyclo-[5.2.1.0.sup.2,6 ]-decylene.

Abstract: Tooth filling and dental fixing using a monomeric polymerizable liquid and a polymer in powder form, which can be a mixture of monomeric and polymeric methyl methacrylates. Adhesion is increased by using a hydroperoxide of the formula ROOH in which R is an optionally substituted alkyl radical.