Methylprednisolone was prescribed the following morning (16 mg) and evening (16 mg). Additionally, postoperative ibuprofen (400 mg, four times daily) and paracetamol (1000 mg, four times daily) were prescribed for 1 week. The patients were instructed to rinse with 0.12% chlorhexidine digluconate twice daily and discontinue the use of their prostheses (if any). Patients were seen for consultation and suture removal 1–2 weeks postoperatively.

Implant placement

Six months (mean 6.3 months, range: 4.8–7.8 months) after the initial bone augmentation procedure, all patients were recalled for implant installation. Prophylactic oral antibiotics (1000 mg amoxicillin, 1 h preoperatively) were given to all patients. A standard incision on the top of the alveolar process with one to two releasing incisions was completed before removal of the previously placed osteosynthesis screws. Using a trephine burr (Komet Dental, Lemgo, Germany, external diameter 3.2, internal diameter 2.6), we retrieved a cylindrical biopsy for later histological evaluation perpendicular to the lateral aspect of the augmented bone, approximately 10 mm from the top of the alveolar crest, including augmented bone and part of the native bone [27]. Finally, a submerged implant (NobelParallel Conical Connection, Nobel Biocare®, Zürich, Switzerland) was installed according to the manufacturer’s guidelines and using an implant surgical guide for optimal positioning. The implant top was positioned approximately 2.5 mm apically from the buccal gingival margin with an insertion torque of 35 Ncm. All patients were seen for consultation and suture removal 1 week postoperatively.

Healing abutment operation

Approximately 7 months (mean 6.7 months, range: 5.7–10.0 months) after implant installation, all patients were recalled for healing abutment operation. A standard incision on the top of the alveolar process was completed before a healing abutment finally was placed after removal of the cover screw. Owing to the minimal incision, no suturing was necessary. The primary implant stability was determined by a percussion test and evaluation of an intraoral radiograph.