To know properties, step-by-step procedure for fabrication and insertion of flexible prosthesis.

Flexible denture base materials were introduced to dentistry by the name of Valplast and Flexiplast in 1950's. Injection molding technique is used for fabrication of various types of prostheses from these materials and fluid resins. Pryor used injection molding technique for introducing unpolymerized acrylic resin into the mold. In the mid 1970's Ivoclar introduced an injection molding system which used an acrylic resin modified for the injection molding process. Recently, numbers of dental manufacturing companies have introduced injection molding systems.

The flexible denture base materials are superpolyamides which are available in the form of granules in cylinders of different sizes. These materials are thermoplastic in nature and needed to be converted into fluid form before pouring into mold under pressure. Each cylinder should be plasticized for 15 to 20 minutes at 550 to 560°F in an electric cartridge furnace before injecting the material into the flask. While injecting, the cylinder should be aligned with opening of flask and the levers of the press should be turned rapidly to apply firm pressure until the springs of the press are fully compressed. The pressure should be maintained for 3 to 5 minutes and the flask should be allowed to bench cool for 15 to 20 minutes before opening.

This technique can be used for fabrication of different types of prostheses from flexible denture base materials and fluid resins.

Singh K, Gupta N. Injection Molding Technique for Fabrication of Flexible Prosthesis from Flexible Thermoplastic Denture base Materials. World J Dent 2012;3(4):303-307.