Patent ID: 7247660

Claim:
A process for the preparation of a dental prosthesis or dental restoration, comprising the step of shaping and curing a low shrinking polymerizable or crosslinkable dental composition comprising a mixture of: (1) at least one crosslinkable and/or polymerizable silicone oligomer or polymer which is liquid at room temperature or which is heat-meltable at a temperature of less than 100° C., and which comprises: at least one unit of formula (FS): wherein: a=0.1 or 2, R 0 , identical or different, represents an alkyl, cycloalkyl, aryl, vinyl, hydrogeno or alkoxy radical, Z, identical or different, is an organic substituent comprising at least one reactive epoxy, or alkenyl ether or oxetane or dioxolane or carbonate functional group, and at least two silicon atoms, (2) at least one aromatic hydrocarbon photosensitizer, having a residual light absorption of between 200 and 500 nm, and selected from the group consisting of the following formulae (VIII), (X). (XII) and (XXII): thioxanthones of formula (VIII): wherein: m=0 to 8, R 17 , identical or different substituent(s) on the aromatic nucleus (nuclei), represent a linear C1-C12 alkyl radical, a branched C1-C12 alkyl radical, a C6-C12 cycloalkyl radical, a radical Ar 1 , a halogen atom, an —OH, —CN, —NO 2 , —COOR 6 , —CHO, Ophenyl, —CF 3 , —SR 6 , —Sphenyl, —SO 2 phenyl, Oalkenyl, or —SiR 6 3 group; xanthones of formula (X): wherein p=0 to 8 anthracene of formula (XII): wherein=0 to 10, and biscoumarins of formula (XXII): wherein: R 18 , identical or different, has the same meaning as R 17 above or represents a group: —NR 6 2 , wherein R 6 represents a linear C1-C12 alkyl radical, (3) at least one dental filler present in a proportion of at least 10% by weight relative to the total weight of the composition, and (4) an effective quantity of at least one borate-type photoinitiator, whose borate residue is: 1′: [B(C 6 F 5 ) 4 ] − 2′: [(C 6 F 5 ) 2 BF 2 ] − 3′: [B(C 6 H 4 CF 3 ) 4 ] − 4′: [B(C 6 F 4 OCF 3 ) 4 ] − 5′: [B(C 6 H 3 (CF 3 ) 2 ) 4 ] − 6′: [B(C 6 H 3 F 2 ) 4 ] − 7′: [C 6 F 5 BF 3 ] − wherein the cationic entity of the borate is: [(Φ) 2 I] + [C 8 H 17 —O-Φ-I-Φ] + [(Φ-CH 3 ) 2 I] + [C 12 H 25 -Φ-I-Φ] + [(C 8 H 17 —O-Φ) 2 I] + [(C 8 H 17 —O-Φ-I-Φ)] + [(Φ) 3 S] + [(Φ) 2 -S-Φ-O—C 8 H 17 ] + [(CH 3 -Φ-I-Φ-CH(CH 3 ) 2 ] + [(Φ-S-Φ-S-(Φ) 2 ] + [(C 12 H 25 - Φ) 2 I] + [(CH 3 -Φ-I-Φ-OC 2 H 5 ] + ; and wherein the composition has a volumetric polymerization and/or crosslinking shrinkage of less than 1.5% v/v.