The retrospective analysis evaluates patients who underwent implant therapy with or without accompanying augmentation procedures between August 1991 and December 2011 in three private practices. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines were followed. To investigate the effect of the different techniques applied on implant survival without overlapping impact of contraindications, the following exclusion criteria were applied: patients with uncontrolled diabetes mellitus, severe cardiovascular diseases (e.g. severe heart insufficiency), organ transplants, intake of bisphosphates and smoking of ≥20 cigarettes/day. Only patients with complete data regarding implantation procedure and implant survival were included. During this time period, a total of 10,165 implants were inserted either with or without augmentation. Seven implants were excluded from the evaluation because the date of implantation was not documented. Thus, 10,158 implants in 3095 consecutively treated patients were included in the retrospective analysis. Of these patients, 1693 (54.7%, 5626 implants) were female, 1401 (45.3%, 4539 implants) were male. For one patient, the sex was not documented. Mean age at the time of the implantation was 52.4 years (14.8 to 89.5). There was no difference regarding age or distribution of sex between patients with or without augmentation. On average, female patients received 3.32 and male patients 3.24 implants per patient.

Surgeries as well as pre- and postsurgical care were performed according to the standard procedures used in the three centres. Implants were inserted according to the manufacturers’ instructions. Patients were scheduled 3 months post-implantation followed by yearly control visits after the completion of the implant-supported restorative therapy.

The following graft materials were used: autogenous bone blocks, autogenous bone particles, Geistlich Bio-Oss (granules or collagen block, Geistlich Pharma AG, Wolhusen, Switzerland), Cerasorb (Curasan, Kleinostheim, Germany), Bioresorb (Implant Direct, Zurich, Switzerland), Bonitmatrix (DOT, Rostock, Germany), Biovin Bovine Bone (OT Medical, Bremen, Germany), Nanobone (Artoss, Rostock, Germany), Osteograf (Dentsply Tulsa Dental Specialities, Oklahoma, USA), Biogran (Biomet 3i, Munich, Germany), Easygraft (Degradable Solutions, Zurich, Switzerland), Endobone (Biomet 3i Deutschland GmbH, Munich, Germany), Pepgen P15 (Dentsply Tulsa Dental Specialities, Oklahoma, USA), Bioseed Oral Bone (Biotissue AG, Freiburg, Germany), Ostim (Heraeus Kulzer, Hanau, Germany), Perioglass (Novabone, Jacksonville, FL, USA) and Rebone (Schütz Dental GmbH, Rosbach, Germany). Autogenous bone was harvested during drilling and from the chin, tibial plateau, iliac crest, maxillary tuberosity and retromolar space.