One day before surgery, the patient started taking antibiotics (amoxicillin 500 mg, three times daily for 7 days) and using a 0.2 % chlorhexidine mouthwash (Corsodyl; GlaxoSmithKline, Utrecht, the Netherlands) for oral disinfection. Following the administering of local anesthesia (Ultracaine D-S Forte; Aventis Pharma Deutschland GmbH, Frankfurt am Main, Germany), an incision was made on the palatal side of the crest with extensions in the buccal and palatal sulcus of the adjacent teeth. For good access to the impacted maxillary canine, a full-thickness buccal mucoperiosteal flap was elevated. After removal of bone overlying the impacted canine with a round drill and a disposable bone scraper (Safescraper® TWIST Cortical Bone Collector, Biomet 3i, Palm Beach Gardens, USA), the impacted tooth (Fig. 3) was extracted with preservation of the alveolar crest. The roots of the adjacent teeth were not exposed. Finally, the primary canine was extracted with a forceps in order to preserve the alveolar crest as long as possible.

Sufficient bone was left on the buccal and palatal side of the alveolus to allow for immediate implant placement (Fig. 4). After drilling the implant site according to the implant system applied, the final twist drill was placed in the prepared socket. Next, the space between the twist drill and the palatal bone wall was augmented with a 1:1 mixture of autologous bone, harvested from the retro molar area, and Bio-Oss® (Geistlich Pharma AG, Wolhusen, Switzerland). Next, the twist drill was carefully removed and an implant (NobelActive RP, 18 mm; Nobel Biocare AB, Göteborg, Sweden) was placed into the prepared implant socket according to the procedure prescribed by the manufacturer, guided by the surgical template (Fig. 5). An 18-mm implant was chosen for good primary stability because of the bone defect. The shoulder of the implant was placed at a depth of 3 mm apical to the buccal and cervical aspect of the prospective clinical crown to provide soft tissue to develop an adequate emergence profile. Good primary implant stability of >45 Ncm was obtained, determined with the measuring device for implant site preparation (Osseocare; Nobel Biocare AB).