Monolithic Zirconia With CAD/CAM Titanium Abutments: A 5-year Prospective Case Series Study

* Background There is a growing interest in restoring function in the posterior maxilla and mandible with dental implants. Next to this, these implants must be restored with crowns which are subject to minimal complications. Companies have introduced the option of screw-retaining and zirconia as crown material. The combination of posterior implants and screw-retained zirconia crowns are widely used, but prospective research on clinical performance and patient centered outcomes are scarce. Even more, 5-years data are lacking. * Main research question To evaluate the clinical performance of Astra Tech Implants EV and Atlantis CustomBase Abutments with full-contour zirconia Atlantis Crowns in the posterior maxilla and mandible. The primary objective of the study is marginal bone level changes by radiological assessments at 5-years follow-up. Secondary objectives are implant and restoration survival, condition of peri- implant mucosa and patients' satisfaction. * Design (including population, confounders/outcomes) The study design is an observational study of a group of patients which were treated 5 years ago with a dental implant and a screw-retained implant-supported zirconia restoration because of a missing tooth in the posterior region. Outcomes: primary outcome is the change in marginal peri-implant bone level 5 years after placing the definitive restoration. Secondary outcome measures will be implant and restoration survival, peri-implant mucosa health and patients' satisfaction using a questionnaire.