Abstract: A coated particle is described, which includes a metal fluoride particle and a polysiloxane coating on the surface of the particle. A dental composition is also described, which includes the coated particle, a polymerizable monomer, and a polymerization initiator.

Abstract: A restorative composition for hard tissue, comprising a paste (A) containing an inorganic calcium phosphate powder, a polymerizable monomer mixture and a polymerization initiator, and a paste (B) containing an inorganic calcium phosphate powder, a polymerizable monomer mixture and a polymerization accelerator, wherein the content of the inorganic calcium phosphate powder in each paste is 75-85% by weight, and each monomer mixture contains a monomer of the formula (1): ##STR1## and a monomer of the formula (2): ##STR2## the content of the monomer (1) accounting for 40-65% by weight of the monomer mixture as a whole. The composition can well adhere to the bone and has a sufficient water resistance. As it generates little heat upon hardening, it is less detrimental to the patient's tissues. Furthermore, the paste has an appropriate consistency, which facilitates homogeneous mixing of the paste and application of the resultant mixture to the affected part by the use of a dispensing apparatus.

Abstract: A dental composition comprising a vinyl monomer containing at least one acidic group in the molecule thereof and an initiator capable of photopolymerizing said monomer by visible light, characterized in that said initiator consisting essentially of:(a) a photosensitizer selected from an .alpha.-diketone, a quinone and a derivative thereof, and,(b) an accelerator selected from a compound containing at least one mercapto group in the molecule thereof is provided by the present invention.

Abstract: An improved process for producing octa-2,7-dien-1-ol which comprises reacting butadiene with water in an aqueous sulfolane solution containing a carbonate and/or bicarbonate of a monodentate tertiary amine in the presence of a palladium compound and a phosphonium salt.

Abstract: A photopolymerizable composition composed of a polymerizable monomer and an initiator capable of polymerizing said monomer upon exposure to visible light, characterized in that said initiator consists essentially of (a) at least one kind of photosensitizer selected from an .alpha.-diketone, quinone, and derivatives thereof, and (b) at least one kind of accelerator selected from an aldehyde containing no amino groups and derivatives thereof.