Comparison of Clinical Performance and Safety of Zirconia vs. Titanium Implants: a Multi-national RCT.

Inclusion Criteria: * Patients must have voluntarily signed the Informed Consent Form before any study related procedures are performed, are willing and able to attend scheduled follow-up visits and agree that the pseudonymized data will be collected, analysed, and published. * Patients must be males or females who are a minimum of 18 years of age. * Patients, who are in need of a single tooth replacement with a dental implant in the premolar-to-premolar area in the mandible or maxilla (excluding lower incisors). * Presence of natural teeth on both sides of the study implant position and opposing dentition (single tooth gap). * Patients with healed extraction sockets, which means that at implant surgery: * Soft tissue coverage of the socket is complete; and * Alveolar bone is reconsolidated (around 16 weeks after tooth extraction). Exclusion Criteria: * Patients with inadequate bone volume where major bone augmentation would be required at implant location. * Inadequate anatomic situation that would prevent prosthetic-driven planning based on CBCT. * Presence of implants neighbouring the study implant. * Patients with inadequate oral hygiene (FMPS ≥ 20%). * Patients with local root remnants. * Patients with inadequate wound healing capacity. * Patients with incomplete maxillary and mandibular growth. * Patients with medical contraindications to implant surgery (uncontrolled bleeding disorders, psychoses, prolonged therapy-resistant functional disorders, xerostomia, weakened immune system, illnesses requiring periodic use of steroids or uncontrollable endocrine disorders. * Patients with drug or alcohol abuse. * Patients with allergies or hypersensitivity to zirconium oxide (ZrO2), yttrium oxide (Y2O3), hafnium dioxide (HfO2), aluminium oxide (Al2O3), and titanium (Grade 4). * Patients with medical contraindications to implant surgery (uncontrolled bleeding disorders, psychoses, prolonged therapy-resistant functional disorders, xerostomia, weakened immune system, illnesses requiring periodic use of steroids or uncontrollable endocrine disorders). * Patients with conditions or circumstances, in the opinion of the Investigator, which would prevent completion of study participation or interfere with analysis of study results, such as history of non-compliance or unreliability. * Pregnancy or intention to become pregnant at any point during the study duration. Furthermore, patients with uncontrolled periodontitis and less than 3 mm of keratinized mucosa at the day of surgery will be excluded from the study. Controlled periodontitis is defined as treated periodontitis with two or less pockets that are \< 4 mm in depth or the existence of ≤ 20% bleeding on probing. If the planned implant position is the second premolar, the adjacent molar must be present. Shortened arches with missing molars are not eligible in such a case.