Abstract: A method of repairing teeth which comprises applying to the teeth a composition comprising (a) an inert, translucent, inorganic particulate filler (b) a polymerizable material comprising a polymerizable prepolymer containing at least two polymerizable ethylenically unsaturated groups and being the reaction product of a urethane prepolymer and a polymerizable ethylenically unsaturated monomer reactive with the urethane prepolymer; the urethane prepolymer being the reaction product of a diisocyanate and a diol; up to 100% by weight of the polymerizable prepolymer of a liquid ethylenically unsaturated monomer which is copolymerizable with the polymerizable prepolymer; and from 0.01 to 10% by weight of the polymerizable material of a photosensitive catalyst capable of curing the composition on exposure to visible light and comprising a photosensitizer selected from fluorenone and an .alpha.-diketone of the formula A.CO.CO.

Abstract: Melt polycondensation of bis(aminophenyl)sulphone with dicarboxylic acid, especially aliphatic dicarboxylic acid, using as catalyst a specified Group VB compound, or metal salt or complex thereof. Typical catalysts are phosphinates or phosphonates in admixtures with metal salts.