softened. The melted polymer, already dislocated by the material that has just been inserted in the equipment, is pushed forward through the injection nozzle, which is in close contact with the mold. The material flows through the opening in the injection channel, into the inside of the mold cavity. The mold is kept closed by the closing cylinder, which applies pressure on the mold. The melted polymer is then forced to penetrate all the parts of the mold cavity, by means of the application of the injection pressure, producing a perfect reproduction of the cavity. The material has to be cooled under pressure below its melting temperature, so that the mold can be opened and the molded part may be ejected from the cavity without deformation or warpage. That cycle repeats itself after the part is removed from the cavity of the mold. (Manas and Roy, 2009).
Figure 10: Diagram of an injection molding equipment.
2.3.4. Evaluation of biocompatibility. According to what has been said before, the PEEK used in the manufacture of multifunctional impression caps and healing abutments is specific for use in implantable products and can be used in contact with elements of the human body (bone, mucosa, fluids, etc.) for a maximum of 180 days. The material shows adequate biological compatibility for the application, being approved in all biocompatibility tests carried out according to the ABNT NBR ISO 10993-1 standard. 2.4. Mechanical evaluation of FGM Multifunctional Impression Cap The mechanical evaluation of the FGM Multifunctional Impression Cap will be divided in the following sections: static compression test and extraction test. 2.4.1. Static test (compression) 22.214.171.124. Materials and methods. This test is carried out to define a load force parameter according to the requirements of standard ABNT NBR ISO 14801:2012 (Dentistry â€“ Implants â€“ Dynamic fatigue test for endosseous dental implants). However, since the components of this report will not be submitted to high-cycle fatigue, as it can be left in the mouth for up to 6 months, only the resistance to static compression will be evaluated as defined by standard ABNT NBR ISO 14801:2012. In this test, the implant is inserted in a tilted block made of a material with an elastic modulus of approximately 3.3 GPa, and the FGM Multifunctional Impression Cap, containing a spherical metal cap with pre-established dimensions is assembled and fixed on the abutment by means of a screw. Then a loading device, adapted to a test machine, applies a compressive force according to what is shown in Figure 11. In that test, the samples are compressed until failure, and the maximum force obtained is recorded. 54 | Arcsys Technical Profile