SERBAN ROSU TISSUE TOLERABILITY OF THE THERMO AND PHOTOPOLYMERIZABLE RESINS USED IN PROSTHETIC RESTORATION AFTER REMOVAL OF THE LOWER FACIAL FLOOR The introduction of the thermo and fotopolymerizable acrylic resins for the manufacture of total prostheses base has revolutionized dentistry in the 20th century. Thermopolymerizable acrylic resins (methacrylic acid derivatives) are found to have a low degree of toxicity on oral tissues after resection of the lower facial floor. It raises the question of thermo and fotopolimerizable acrylic resins toxicity compared with transplanted tissues from outside the oral cavity, in these cases compared with free osseomiocutaneous fibular flap. With the help of these resins, the restoration of the mastication, swallowing, phonation and physiognomy functions was achieved. The impact of free flaps in reconstruction of the mandible and oral floor and osseointegration of dental implants ensuring the stability of dentures are remarkable, allowing the reconstruction of the lower facial floor in a very high degree and the restoration of all functions.