Where a deficient posterior alveolar ridge and increased pneumatization of the maxillary sinus appeared, implants were inserted with simultaneous sinus floor augmentation (one‐step procedure) (osteotome technique, or lateral window technique) or after a previous sinus floor augmentation with bone grafting (two‐step procedure).

Sites that exhibited localized horizontal bone defects were treated with bone graft plus barrier membranes, according to the principle of guided bone regeneration (GBR) with a simultaneous approach or with a GBR staged approach. The sites with localized horizontal bone defects were treated with a bone graft plus degradable bi‐layer collagen membranes only.

When necessary, implants were treated with graft material, autogenous bone in particulate form or autogenous bone mixed with xenograft biomaterial or xenograft biomaterial. All grafts were placed underneath the resorbable membranes.

The autogenous bone in particulate form was harvested either during the preparation of the implant recipient sites or from other intraoral donor sites (mental symphysis and ramus mandibularis). The xenograft biomaterial used in all treatments was deproteinized natural material of bovine origin. Abutments were connected after a healing period of 2 to 6 months by the same clinician who performed the implant placement. Radiographic data were collected to establish a measurement reference for follow‐up controls, and the probing depth around the implants was measured and recorded.

After surgery, all patients were instructed on how to perform oral hygiene (mouth rinses using chlorhexidine at 0.2% for 2 weeks). In addition, patients received antibiotic coverage for 5 days (up to 8 days for implants placed in sites with a soft or hard tissue defect) and non‐steroidal analgesics for 3 to 5 days or more if needed. Patients were recalled 7 to 14 days after surgery for suture removal.

For all implants inserted either in the mandible or in the maxilla using a standard technique, a healing period of 2 months was observed. The healing period was extended to 3 to 6 months, depending on the extent of the bone defect, for implant placed with GBR or sinus lifting technique.