The invention provides a storage stable dental composition comprising a volatile organic solvent and a polymerizable material enclosed by a package, which includes a closure, such as a cover or plug and a container made of a copolymer of a cycloolefin and an open chain olefin. In accordance with an embodiment of the invention is provided a stored packaged dental product by the process including: enclosing a dental composition in a package with at least a substantial portion of an injection molded thermoplastic copolymer of a cycloolefin and an open chain olefin, and storing the dental composition in the package for at least 1 week. <；IMAGE>；
