A hermetically sealed enclosure for use in fabricating a polymeric dental article. Monomers are mixed within the enclosure by squeezing a first burst pouch to break a first burst seal between it and a second burst pouch and manipulating the enclosure by hand to initiate a polymerization reaction while the enclosure remains hermetically sealed. A second burst seal between the second burst pouch and a dispensing funnel chamber is broken by further squeezing which forces the mixture into the dispensing funnel chamber. The mixture is dispensed from an outlet of the dispensing funnel chamber by further squeezing after a tear-off strip closing the outlet has been torn off.