A dental appliance made of an olefin polymer is directly formed via rapid prototyping without the use of an intermediary physical mold. A polymer precursor solution includes one or more olefin-containing monomers and/or oligomers, an olefin polymerization catalyst, and a UV absorbing agent to limit penetration of the UV light through the polymer precursor solution. One or more reactions of the polymer precursor solution are modulated in response to UV light, and the polymer precursor solution may further include an inhibitor (quenching agent) configured to modulate those reactions. The polymer precursor solution can be deposited using UV-cured stereolithographic or 3D printing methods to form appliances exhibiting improved elongation at break characteristics and suitable stress resistance.

Disclosed herein is a multilayer coating system present on a substrate and including at least two coating layers L1 and L2 different from one another, namely a first coating layer L1 applied over at least a portion of the substrate, and a second topcoat layer L2 applied over the first coating layer L1, where the topcoat layer L2 is formed from a coating composition including at least one block copolymer containing a backbone and at least two blocks B1 and B2 and side chains S1 and S2 including different polymeric moieties M1 and M2. Also disclosed herein are a method of preparing said multilayer coating system, a coated substrate obtainable therefrom, and a method of using a coating composition including the block copolymer for improving, in particular for increasing, the chromaticity of the multilayer coating system.

A dental appliance made of an olefin polymer is directly formed via rapid prototyping without the use of an intermediary physical mold. A polymer precursor solution includes one or more olefin-containing monomers and/or oligomers, an olefin polymerization catalyst, and a UV absorbing agent to limit penetration of the UV light through the polymer precursor solution. One or more reactions of the polymer precursor solution are modulated in response to UV light, and the polymer precursor solution may further include an inhibitor (quenching agent) configured to modulate those reactions. The polymer precursor solution can be deposited using UV-cured stereolithographic or 3D printing methods to form appliances exhibiting improved elongation at break characteristics and suitable stress resistance.

A copolymer and its use as coating whereby the copolymer comprises a first monomer of the general formula (I)

##STR00001##

and a second monomer of the general formula (II)

##STR00002##

wherein Y is selected from the group consisting of CH.sub.2Z.sub.3, NHCOR.sub.5, CONHR.sub.6, OCOR.sub.7, COOR.sub.8 and OR.sub.9, and where Z.sub.1, Z.sub.2, and Z.sub.3 are selected from the group consisting of fluoro, chloro, bromo, iodo, hydroxyl, toluene-4-sulfonyloxy and methylsulfonyloxy. R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently from each other selected from the group consisting of linear or branched C.sub.1-C.sub.30 alkyl, a linear or branched C.sub.2-C.sub.30 alkenyl, a linear or branched C.sub.2-C.sub.30 alkynyl, sulfo, nitro, amino, hydroxy, oligo(C.sub.2 to C.sub.4-alkylene glycol), NHCOR.sub.5, CONHR.sub.6, OCOR.sub.7, COOR.sub.8 and OR. R.sub.5, R.sub.6, R.sub.7, R.sub.8 and R.sub.9 are selected from the group consisting of a linear or branched C.sub.1-C.sub.30 alkyl, a linear or branched C.sub.2-C.sub.30 alkenyl and a linear or branched C.sub.2-C.sub.30 alkynyl.