PEEK Prostheses in the All-on-4 Concept Using Zygomatic Implants for Full-arch Rehabilitation.

Inclusion Criteria: * Subjects who, in the opinion of the Investigator, are able to understand this clinical study, co-operate with the procedures and are willing to return to the clinic for all the required post-operative follow-ups. * Subjects who are able to give voluntary, written informed consent to participate in this clinical study and from whom consent has been obtained. Exclusion Criteria: * Female Subjects who are pregnant. * Subjects who are known drug or alcohol abusers or with psychological disorders that could affect follow-ups or treatment outcomes. * Subjects with any condition that would compromise their participation and follow-up in this clinical study. * Subjects who are currently enrolled in a clinical study.