Caroliene Meijndert

22 Chapter 2 procedure or with an augmentation procedure with demineralized bovine bone mineral in combination with either a collagen (CM) or an expanded polytetrafluoroethylene (e-PTFE) membrane. Implant survival was 94.6% in the control group, 91.9% in the CM group and 92.6% in the e-PTFE group, without any significant differences. It must be noted that implants were positioned in both the anterior and posterior region of maxilla and the mandible and with a variety of superstructures. Kuchler & Von Arx (2014) showed in their systematic review on horizontal ridge augmentation prior to implant placement in the anterior maxilla that different methods are available to create the basis needed for reliable implant placement. Survival rates of implants, with an up to 4 years follow-up, placed in such reconstructed areas is ranging from 93.5% to 100%. No such data are available for long-term implant survival specifically for single-tooth replacement in the aesthetic region. To date, limited long-term studies are available on dental implants in the maxillary aesthetic region and no long-term studies are available comparing the long-term results of different augmentation procedure techniques with regard to the changes in hard and soft peri-implant tissues in a randomized clinical trial. Therefore, the aim of this randomized controlled trial was to assess the 10-year effects of three different augmentation techniques (augmentation with chin bone, augmentation with chin bone plus a Bio-Gide® membrane and augmentation with Bio-Oss® plus a Bio-Gide® membrane) for implant-supported restorations in the maxillary aesthetic region regarding clinical and radiographic parameters, and patient-centred outcomes. Materials and Methods Patient selection Ninety-three consecutive patients, fulfilling the selection criteria, were selected from the Department of Oral and Maxillofacial Surgery in Groningen (University Medical Center Groningen, Groningen, the Netherlands) and from the Department of Oral and Maxillofacial Surgery in Drachten (Nij Smellinghe Hospital, Drachten, the Netherlands). All patients (44 men, 49 women, mean age at time of implant surgery 33.3 ± 13.0 years) had a single tooth diastema in the anterior region of the maxilla. The planned treatment site had to show a horizontal bone deficiency, making a bucco-palatinal local ridge augmentation necessary to obtain sufficient bone volume for reliable placement of a dental implant. Study design with in- and exclusion criteria, together with 1-year results, has been reported in detail by Meijndert et al. (2007, 2008).