The cumulative survival rate of the presented ceramic implant was comparable to the reported survival rate of titanium implants when immediately restored. However, the frequency of increased radiographic bone loss (>2 mm) after 1 year was considerably higher as compared to conventional two-piece titanium implants. The presented zirconia implant can therefore not be recommended for clinical usage.

A high frequency of increased radiographic bone loss (>2 mm) after 1 year around the presented one-piece zirconia implant system was found. The bone loss seems to be higher compared to the very limited availability of zirconia implant data. Therefore, within the limits of the present investigation, it may be concluded that the presented zirconia implant system possibly performs inferior to conventional titanium implants and to other zirconia implants regarding peri-implant bone loss.

All PTFE membranes were effective barriers against bacterial passage in vitro. However, d-PTFE favored S. oralis biofilm formation.

Prolonged inflammation and reactive oxygen species (ROS) generated around an implanted biosensor are the primary causes of the foreign body response, including encapsulation of biosensor membranes. We have previously demonstrated that TiO2 surfaces reduce ROS. Here we investigated the potential of using the anti-inflammatory properties of TiO2 in the design of biosensor membranes with improved long-term in vivo transport properties. Micropatterned Ti films were sputtered onto quartz surfaces in a series of hexagonally distributed dots with identical coverage area of 23% and dot size ranging from 5 to 100 microm. The antioxidant effect of the surfaces was investigated using a cell-free peroxynitrite donor assay and assays of superoxide released from stimulated surface-adhering neutrophils and macrophages. In all three assays, the amount of ROS was monitored using luminol-amplified chemiluminescence. Patterned surfaces in all experimental models significantly decreased ROS compared to the etched surfaces. In the cell-free experiment, the ROS reduction was only dependent on fractional surface coverage. In the cell experiments, however, a dot-size-dependent ROS reduction was seen, with the largest reduction at the smallest dot-size surfaces. These results indicate that micropatterned surfaces with small dots covering only 23% of the surface area exhibit similar antioxidative effect as fully covered surfaces.

While titanium implants are generally recognized as having excellent biocompatibility, the mechanistic basis for this has yet to be established. We previously demonstrated that TiO2, found on surfaces of titanium, has antioxidant properties that degrade the reactive oxygen species (ROS) which mediate the inflammatory response. We hypothesized that the antioxidant mechanism was similar to that known to mediate photocatalysis by titanium oxides. Specifically, we investigated whether the electronic or valence state of the surface titanium atoms mediates the catalytic degradation of ROS. Surface Ti(IV) atoms in TiO2 and SrTiO3 single crystal substrates were converted into Ti(III) while maintaining the bulk crystalline structure by vacuum annealing or Niobium doping. The degradation of both chemically-induced and neutrophil-derived ROS were significantly increased by changing the valence state of surface titanium. These results suggest that titanium-mediated degradation of ROS is through a catalytic mechanism. Furthermore, we describe a series of novel biomaterials that have antioxidant properties superior to those of titanium.