Fracture load of titanium crowns coated with gold or titanium nitride and bonded to low-fusing porcelain.

Background: It is difficult to achieve a reliable bond between the titanium copings and veneering porcelain of restorations.

Objective: The purpose of this study was to investigate the effect of various treatments on the fracture load of bonded titanium and porcelain components of crown restorations.

Methods: In this study, the surfaces of titanium copings (n=6) were either airborne-particle abraded with Al(2)O(3) particles, sputter coated with gold, or coated with TiN. Gold ceramic crowns served as the control group (n=6). The effects of these treatments on the fracture load of bonded titanium and low-fusing porcelain were investigated. A universal testing machine was used to determine the fracture load (N) of the crowns. All data were compared using 1-way ANOVA and the post hoc multiple range Tukey test (α=.05). In addition, the metal ceramic interfaces were examined by scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS).

Results: The gold-coated titanium (1035 +/-41 N) and TiN-coated titanium (969 +/-93 N) had significantly higher fracture loads (P<.001) than the airborne-particle-abraded titanium ceramic crowns (865+/-44 N). The gold-coated and TiN-coated titanium specimens demonstrated fracture loads similar to that of gold ceramic crowns (1026 +/-50 N) [corrected]. SEM/EDS showed that after the crowns fractured, the gold control group and gold- and TiN-coated titanium specimens had more adherent porcelain on their surfaces than the uncoated titanium that was airborne-particle abraded with Al(2)O(3) particles.

Conclusions: The in vitro fracture load of titanium crowns coated with gold or titanium nitride and bonded to low-fusing porcelain is comparable to that of gold ceramic crowns, and higher than loads observed with uncoated titanium airborne-particle abraded with Al(2)O(3) particles.