Of the 10,158 implants, 58.2% (5916 implants) were inserted using an augmentation procedure. The minimal observation period until the last control visit or until explantation was 0 days (day of implantation); the maximum period was 20.2 years. Distribution of analysed implants according to the period of observation is shown in Table 1.

A total of 4.53% (460 implants) of all implants were lost during the observation period of 20.2 years. Analysis of early and late implant loss revealed that 16 implants (0.38%) without and 19 implants (0.32%) with augmentation were extracted before connection to the suprastructure, whereas 227 implants (5.35%) without and 198 implants (3.35%) with augmentation were lost after the attachment of the suprastructure within a 20.2-year observational period. Statistical analysis using Kaplan-Meier method and log-rank test revealed significantly better (p = 0.0025) survival curves for implants inserted with augmentation (96.33% of functional implants) compared to implants without augmentation (94.27% of functional implants) (Table 2 and Fig. 1). This was also true if only single-crown implants were evaluated, where the proportion of surviving implants was 98.84% (23 explantations of 1980 implants) with augmentation and 97.01% (34 explantations of 1136 implants) without augmentation (p = 0.0028).