The series of studies conducted in this thesis showed that there are several ways to enhance the performance of fixed restorations regarding the application of zirconia. One possible way is to change the sintering procedure of zirconia, so that the physical properties of zirconia such BFS, density or grain size can also be changed. In the other hand, with the experimental zirconia-silica coating technique, the bond strength of zirconia frameworks can be improved, in order to reduce the clinic failure rate caused by debonding. Besides the improvement of zirconia itself, it can be also used to reinforce other materials as a substitute to the brittle veneering porcelains. Furthermore, the zirconia nanoparticles can be used as fillers for both traditionally or industrially fabricated resin composite, whose in vitro performance is still quite good. With the increased bond strength of zirconia and resin composite, the composite veneered zirconia framed fixed restorations can be studied in the future.