Immediate Versus Late Placement

Patients in need of a single implant in the premaxilla will be invited to participate in this multicenter randomized controlled trial (RCT). Prior to surgery, a small-field low-dose cone beam computed tomography (CBCT) is taken to verify the integrity of the facial bone wall and an adequate amount of apical and palatal bone dimensions. Sixty patients will be randomly allocated to the test group or control group in 6 centers. Each center receives 10 sealed envelopes (5 are internally labelled with 'delayed implant placement' and 5 with 'immediate implant placement').

For each patient a digital planning is performed in implant planning software and a tooth-supported surgical guide is fabricated prior to tooth extraction.

In the control group, alveolar ridge preservation is performed following tooth extraction. After a healing period of 4 months, a single implant is installed.

In the test group, a single implant is installed immediately after tooth extraction and ridge preservation is performed by filling the gap between the facial bone wall and the implant surface.

A provisional crown is placed at the day of implant surgery, which is replaced by a permanent one 3m later.

Six months after tooth extraction and subsequent ridge preservation, the need for soft tissue grafting is assessed on the base of predetermined criteria (primary outcome measure). Soft tissue augmentation is performed by inserting a palatal connective tissue graft (CTG) into the buccal mucosa at the implant site.

Secondary outcome measures include 3D hard and soft tissue changes as well as clinical, aesthetic, patient-reported and clinician-reported outcomes.