The study was started with 94 patients with 130 implants. At the end of the study (5-year post-loading), 76 patients with 104 implants were considered for analysis. Dropouts were distributed over the time of the study as described in Table 1. The majority of dropouts occurred early in the study phase. The reasons for the dropouts were variable as described in Fig. 1.

The demographic and clinical parameters have been described in detail in [10]. Table 2 shows a further characterisation of patients. Four implants were placed immediately after tooth extraction while the majority of the implants were placed on healed extraction sites. On average, the implants were placed slightly subcrestally (0.32 ± 0.53 mm below crestal bone level). Two-stage surgery was applied in 66.7% of the cases, one-stage surgery in 33.3%. Twelve implants were loaded with a provisional beforehand. Single crowns were fixed on 103 implants, while a fixed partial denture was used in 10 cases (18 implants). The restorations were either cement-retained (81.4%) or screw-retained (18.6%).

Two early implant losses in the healing phase were recorded, one due to infection and another due to radiolucency. Both implants had to be explanted prior to loading. After baseline, three implant losses were reported: two implants had to be extracted due to implant mobility (54 and 60 months post-loading), another due to peri-implantitis (45 months post-loading). The mean follow-up time was 62.3 months, the maximum 82 months. The cumulative proportion surviving rate up to 7-year post-loading was 96.6% (Kaplan-Meier, Fig. 2) with confidence interval lower bound 89.3% and upper bound 98.9%.

Further reported complications were peri-implant bone loss (> 2 mm) in three patients. Two of them started in the healing phase, the third in the follow-up period due to cement remains. All three could be treated or were still under treatment at study end. On the prosthetic level, three complications were reported as follows: two crown loosening and one chipping of crown. All crowns could be replaced with new crowns without further problems.