improved permanent soft denture liners are disclosed which consist substantially of an amount of one or more polysiloxanes selected from acryloxyalkyl and methacryloxyalkyl - terminated polydialkylsiloxanes in which the polysiloxane is crosslinked by a material selected from suitable heat , light or chemically activated initiators with or without crosslinking agents . the preferred embodiments are visible light activated and can be applied , fitted , cured and installed in one sitting .