Abstract: (Meth)-acrylic acid derivatives of tricyclodecanes of the formula ##STR1## in which R.sup.1 and R.sup.2 are identical or different and denote hydrogen, lower alkyl, lower alkoxy, halogen or trifluoromethyl and R.sup.3 and R.sup.4 are identical or different and represent the group ##STR2## wherein X denotes a divalent bridge member from the group ##STR3## and Y denotes a divalent bridge member from the group ##STR4## and wherein R.sup.5 represents hydrogen or methyl and R.sup.6 represents lower alkyl or phenyl, have been found. Dental compositions in which the present (meth)-acrylic acid derivatives of tricyclodecanes are used, exhibit considerably less polymerization shrinkage.

Abstract: In a photopolymerizable composition comprising(a) at least one ethylenically unsaturated photopolymerizable monomer.(b) at least one photoinitiator selected from organic mono- and/or di-carbonyl compounds and(c) a photoactivator, the improvement which comprises employing as said photoactivator at least one alkylaminoarylsulphonyl compound of the formula ##STR1## in which R.sub.1 and R.sub.2 each independently is a hydrogen atom or an alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or alkaryl group which has 1 to 11 carbon atoms and is optionally substituted by at least one hydroxyl, amino, epoxy, urethane, urea, ether of ether group, or R.sub.1 and R.sub.2 together form a 3- to 6-membered ring, which optionally contains nitrogen, oxygen or sulphur as a hetero-atom,R.sub.3 independently of R.sub.1, has any of the meanings given for R.sub.1 or is a group of the formula ##STR2## R.sub.4 and R.sub.

Abstract: A rotary valve has a valve body with a pair of fluid ports providing fluid exits on a face of the valve body. The fluid ports are connected to corresponding fluid channels in the valve body extending between the fluid ports and fluid inlet connections to the valve body. A fluid control plate is positioned in contact with the face of the valve body and extends across the fluid ports. The control plate has a fluid channel therein which is dimensioned to extend between the fluid ports in one position of the valve plate. The valve plate is axially mounted on an output shaft of a drive motor which is connected to the valve plate by a coupling shaft. The face of the valve body and the contacting face of the valve plates are ground precisely flat and after hard anodizing are coated with a low friction coating such as molydisulphide. The motor is arranged to urge the valve plate parallel to and against the face of the valve body by the weight of the motor and the connecting elements between the motor and the valve.

Abstract: The invention relates to (meth)acrylic acid esters of compounds of Formula (I) as defined infra and methods for their preparation. The esters formed can be used to provide dental repair material and also to provide adhesive or sealing agents. In addition, the invention includes a process for preparing compositions which harden in the absence of oxygen by admixing a compound of the invention with an initiator.

Abstract: The invention relates to the provision of dental compositions containing a polymerizable (meth)acrylic acid ester of the formula Id as defined herein and includes methods for filling or repairing teeth in warm-blooded animals.

Abstract: The invention includes formulated dental filling materials comprising a polymerizable organic plastics material containing inorganic fillers, which filling material comprises at least two pastes in intimate admixture with one another in a paste/paste system in which hardening is initiated by means of a peroxidic initiator and an accelerator, wherein said at least two pastes contain different inorganic fillers with different chemical constitutions such that one of said at least two pastes contains filler with a substantially higher proportion of elements with high atomic number than does the other of said at least two pastes. Also included in the invention is a dental filling pack containing said formulated dental filling materials as well as a method for their use.