One of the most common complications of cemented prostheses is aseptic loosening of the implant, which is often due to mechanical breakdown at the bone-cement interface. To improve the characteristics of PMMA, the addition of fluoride has been proposed, which, without jeopardising its mechanical qualities, should provide better integration with the surrounding bone. An experimental study was performed in 4 sheep. A cylinder of cement (with and without fluoride) was inserted in the meta-epiphysis of the distal femur. A clinical study followed 7 patients. The cement with added fluoride was used as a filler after the curettage of a benign tumour located in the meta-epiphysis around the knee. Histological results in animals combined with long-term radiographic results in humans have shown the positive influence of fluoride in the cement, as it allows better integration of the cement with the surrounding bone.