The present randomized controlled trial showed no important differences between early and delayed loading of implants in the edentulous maxilla after 5 years of function. A favourable long-term marginal bone response to the sandblasted large-grit acid-etched (SLA) surface was observed. Technical complications were mainly resin-related which could be avoided by the use of a lingual gold onlay. It is concluded that early loading of SLA-surface implants for support of full-arch bridges represents a viable therapy for the totally edentulous maxilla.

The implant survival was 95.1%. The mean value of bone loss after 10 years was 1.07 mm. Peri-implantitis were noted at the 5-year follow-up for one patient with a previous history of periodontitis; this patient did not attend the 10-year follow-up. This study shows that sandblasted and acid-etched implants offers predictable long-term results as support for full-arch maxillary prostheses.

Fracture or wear of the reconstruction materials were considered predictable risks when using resin-based suprastructure materials. Status of opposing dentition and length of cantilevers did not confer additional risk. The use of a lingual gold onlay indicated prevention of resin-related complications. Future research should focus on the suprastructure materials to predict better overall treatment results of implant-supported full-arch bridges in the edentulous maxilla.

The semiconducting properties of sputtered magnetite (Fe304) and oxidized magnetite layers with different Fe(II) contents were compared with the passive film on iron. Electrochemical impedance spectroscopy and photoelectrochemical experiments were carried out in borate buffer, pH 8.4. An evaluation of the impedance data according to the Mott-Schottky concept showed that the capacitance of all films is linked with their doping concentrations rather than their thicknesses and that the doping species of the passive film on iron is Fe(II). For the passive film a potential-dependent doping concentration was found. Photoelectrochemical investigation of the passive film and the sputtered oxide layers showed that for low doping concentrations, the photocurrent increases with doping, whereas for high doping concentrations, an increase in doping leads to a decrease of the photocurrent. Possible causes for this effect are discussed. Further, the combination of a light reflectance technique with photocurrent measurements allowed consideration of light absorption effects in the data treatment and separation of photocurrent contributions from the space-charge layer from filmthickness effects.