Abstract: A process for producing a radiopaque cement comprises reacting a polymer containing free carboxyl groups (generally a homo or copolymer of acrylic acid) with a particulate acid-leachable source of polyvalent metal ions (such as an acid-leachable glass) in the presence of water and strontium fluoride.

Abstract: Alkaline earth metal aluminofluorosilicate glasses suitable for use as ion-sources in the poly(carboxylic acid) cement compositions contain strontium in order to provide radiopacity. The invention also provides methods for making poly(carboxylate) cement using the glasses of the invention as ion-sources.

Abstract: A process for producing a radiopaque cement comprises reacting a polymer containing free carboxyl groups (generally a homo or copolymer of acrylic acid) with a particulate acid-leachable source of polyvalent metal ions (such as an acid-leachable glass) in the presence of water and strontium fluoride.

Abstract: An adhesion promoter, suitable for improving the adhesion of composite dental material to tooth enamel, comprises a solution in a volatile organic solvent therefor, such as a lower alkanol, of a polyethylenically unsaturated monophosphate or salt thereof, containing a monophosphate radical and at least three ethylenically unsaturated groups (preferably terminal ethylenically unsaturated groups) per molecule. Preferred polyunsaturated phosphates are monophosphates of polyhydric alcohols containing at least four hydroxyl groups per molecule in which at least three hydroxyl groups are esterified with an ethylenically unsaturated carboxylic acid, and especially preferred polyunsaturated phosphates (which are provided as new compounds) are those of the formula: ##STR1## in which: R is an aliphatic (optionally interrupted by one or more oxygen atoms) cycloaliphatic or aryl radical having a valency of n+1 and containing from 4 to 16 carbon atoms,R.sup.1 is a hydrogen atom, alkyl C.sub.1 -C.sub.

Abstract: Apparatus and methods are disclosed for the selective dissolution of a predetermined metal from, for example, a metal-metal combination. The metal or the metal-metal combination is made the working electrode of an electrolytic cell whose other electrode is electrolytically inert in the cell in use. The working electrode is held at a substantially constant electrical potential relative to a standard calomel electrode, and this potential and the pH of the electrolyte are selected such that the electrical energy passing through the cell during a selected time period is dependent on the amount of the predetermined metal electrolytically dissolved and substantially independent of any other metal which may be present.