Abstract: An anaesthetic apparatus having a plurality of vaporizers is provided which utilizes an interlocking device which prevents more than one vaporizer from being activated at one time. The interlock device can be used with any number of vaporizers mounted side-by-side. The interlock device comprises a cam follower which is adapted to be received in a rotating cam which is used to activate the vaporizer. The cam follower is connected to a pair of cranks which activate bars which interact with bars on adjacent interlocking devices, when one of the interlocking devices is activated, thereby locking all the other vaporizers in a inoperative position. Also provided is a safety lock connector which is used for connecting hose to an anaesthesia apparatus.

Abstract: A process for producing a radiopaque cement comprises reacting a polymer containing free carboxyl groups (generally a homo or copolymer of acrylic acid) with a particulate acid-leachable source of polyvalent metal ions (such as an acid-leachable glass) in the presence of water and strontium fluoride.

Abstract: Alkaline earth metal aluminofluorosilicate glasses suitable for use as ion-sources in the poly(carboxylic acid) cement compositions contain strontium in order to provide radiopacity. The invention also provides methods for making poly(carboxylate) cement using the glasses of the invention as ion-sources.

Abstract: A process for producing a radiopaque cement comprises reacting a polymer containing free carboxyl groups (generally a homo or copolymer of acrylic acid) with a particulate acid-leachable source of polyvalent metal ions (such as an acid-leachable glass) in the presence of water and strontium fluoride.

Abstract: An adhesion promoter, suitable for improving the adhesion of composite dental material to tooth enamel, comprises a solution in a volatile organic solvent therefor, such as a lower alkanol, of a polyethylenically unsaturated monophosphate or salt thereof, containing a monophosphate radical and at least three ethylenically unsaturated groups (preferably terminal ethylenically unsaturated groups) per molecule. Preferred polyunsaturated phosphates are monophosphates of polyhydric alcohols containing at least four hydroxyl groups per molecule in which at least three hydroxyl groups are esterified with an ethylenically unsaturated carboxylic acid, and especially preferred polyunsaturated phosphates (which are provided as new compounds) are those of the formula: ##STR1## in which: R is an aliphatic (optionally interrupted by one or more oxygen atoms) cycloaliphatic or aryl radical having a valency of n+1 and containing from 4 to 16 carbon atoms,R.sup.1 is a hydrogen atom, alkyl C.sub.1 -C.sub.