Dental device that expands the mouth to improve the field of view inside the mouth, and extracts saliva from the work area inside the mouth

Non-metal building materials for use in oil and/or gas handling installations, microporous material or silica material in the nature of spacers, filling materials or blocking materials; non-metal building materials for use in pipes, and pipelines, in particular double-walled pipelines, namely, pipe-in-pipe systems, namely, spacers, filling materials or blocking materials; flexible microporous sheets placed between two metal or non-metal casings in the nature of spacers, filling materials or b...