Method of repairing teeth using a composition which is curable by irradiation with visible light

A method of repairing teeth which comprises applying to the teeth a composition comprising:

• (a) from 60 to 90% by weight of the composition of an inert, translucent, inorganic particulate filler of which at least 50% of the particles have a maximum dimension not greater than 500 microns and a Knoop hardness of at least 100, and
• (b) a polymerisable material comprising:
• a polymerisable prepolymer containing at least two polymerisable ethylenically unsaturated groups and being the reaction product of a urethane prepolymer and a polymerisable ethylenically unsaturated monomer reactive with said urethane prepolymer of the formula:
• ##STR29## wherein R.sub.3 is hydrogen or methyl and each of R.sub.6 and R.sub.7 is hydrogen or one of R.sub.6 and R.sub.7 is hydrogen and the other is methyl;
• said urethane prepolymer being the reaction product of a di-isocyanate selected from the group consisting of 4,4'-di-isocyanatodiphenylmethane, hexamethylene di-isocyanate, 4,4'-dicyclohexylmethane di-isocyanate and 2,4-tolylene diisocyanate, and a diol being the condensate obtained by reacting 2,2-bis-(p-hydroxyphenyl)propane and propylene oxide in a molar ratio of 1:2;
• up to 100% by weight of the polymerisable prepolymer of a liquid ethylenically unsaturated monomer which is copolymerisable with said polymerisable prepolymer selected from the group consisting of methyl methacrylate, ethylene glycol dimethacrylate, hydroxyethyl methacrylate, triethylene glycol dimethacrylate and allyl methacrylate;
• and from 0.01 to 10% by weight of the polymerisable material of a photosensitive catalyst capable of curing the composition on exposure to visible light and comprising:
• a photosensitiser selected from fluorenone and an .alpha.-diketone of the formula A.CO.CO.A, wherein the groups A are aliphatic, aromatic, cycloaliphatic, aralkyl or alkaryl, or together form a divalent aliphatic or aromatic group which together with the carbonyl groups forms a cyclic structure, and a reducing agent capable of reducing the photosensitiser when the photosensitiser is in an excited state, and curing the composition by irradiating said composition with visible radiation in the range 400 m.mu. to 500 m.mu..