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: A prosthetic device having at least part of the surface thereof made of a material having a surface energy, as hereinbefore defined, in the range 50 erg cm.sup.-2 to 100 erg cm.sup.-2, for example, made of a plastics material which is a copolymer comprising repeat units having the structure --CH.sub.2 --CH.sub.2 --O-- and other units capable of stabilizing the copolymer in water, the copolymer comprising at least 10% by weight of units having the structure --CH.sub.2 --CH.sub.2 --O-- and no more than 95% by weight of said units.