The use of fiber composite technology in the creation of metal-free implant prostheses may solve many of the problems associated with a metal alloy substructure such as corrosion, toxicity, complexity of fabrication, high cost, and esthetic limitations. Laboratory and clinical research evaluating glass fiber-reinforced composite prostheses used to restore and replace teeth has shown that these materials exhibit excellent mechanical properties and can form a chemical bond to resin-based veneer materials such as those used in the fabrication of certain types of implant prostheses. Two different designs of fiber-reinforced composite implant prostheses have been developed and placed in human subjects. One design (screw-retained, retrievable prosthesis) is used with implant abutments that allow for screw-retained prostheses; the other design is used with abutments that retain prostheses with a luting material. Both designs are described in this article. The prostheses have functioned well in a small group of preliminary subjects, but clinical trials with larger subject populations are needed to more completely evaluate the potential of fiber-reinforced composites in implant prosthodontics.